March 15, 2015


Random finding (plus pi)

The best part of parenting (so far)? Helping your kids overcome things you struggled with. It’s at least in the top 5.

by Peter Attia

Read Time 6 minutes

The best part of parenting (so far)? Helping your kids overcome things you struggled with. It’s at least in the top 5.

Last Saturday my daughter came home from dance class—something she normally loves—and seemed upset. A bit of prodding led to the cause: a girl in her dance class told her she was “as fat as a hippopotamus.”  My first reaction (note to self: probably not the right one) was to laugh out loud, given that my daughter is probably in the 10th percentile of weight for her age. I’m worried she’s too skinny!

Of course I realized quickly the “facts” were irrelevant in this case. Her body habitus was moot. But her feelings were hurt, and as we all know this wouldn’t be last time someone said something to her—true or untrue—that would hurt her feelings.  I won’t go through the entire discussion we had, as I’m sure those of you with kids have already been through this, and those of you without kids probably aren’t worrying about this type of interaction.

I did, however, decide to tell her about all the people who dislike me and say mean things about me, usually things that aren’t true. She was shocked, “Like what, daddy?” I gave example after example. She was amazed—and relieved, I suspect—to know that she wasn’t alone and that I was able to shrug it off after temporarily being upset by it. I even told her about folks posting videos on YouTube specifically attacking me.

So, when our little talk was over she asked if she could see one of the videos I alluded to. I was a bit hesitant, if only for some of the language used when folks rant against my existence (if she’s going to learn choice 4-letter words in earnest, it should be from me after all), but I figured it was a good idea. She could actually see for herself that people say mean things about her dad and he’s still, more or less, ok.

Which brings me to the point of this quasi-post…

In searching for said YouTube videos, which I eventually found, I stumbled across two talks I gave last year which made their way online, unbeknownst to me.

In keeping with the current spirit of my co-op blog posts, below are links to the two talks.

Talk 1: Evidence for (and against) the dietary guidelines restricting saturated fat



This talk is an updated version of a talk I gave a few years ago and shared on the blog, in 2012 I think. Even if you watched the earlier version of the talk, if you find this question interesting—what is the case for restricting saturated fat (SFA) intake—it’s worth watching this version. I find this particular topic especially interesting because I think it highlights the challenge we all have, myself included, in setting aside bias when confronted with new information. (My friend Carol’s amazing book, Mistakes Were Made (But Not By Me) cannot be recommend highly enough for people who want to understand how cognitive dissonance wreaks havoc in even otherwise functioning societies.)

And contrary to what some (perhaps many) of you might think, I don’t believe this is a settled debate across the board. What do I mean by that (i.e., “across the board”)? Certainly in this presentation I try to make the case that the continually falling recommendations for SFA—from 12% to 10% to 8% to 5% of total calories—are not supported by convincing science. In fact, such recommendations likely do harm, courtesy of the “substitution effect,” i.e., people end up eating more of other things—namely, sugars and omega-6 polyunsaturated fats (n-6 PUFA)—that likely cause greater metabolic derangement.

However, some readers may interpret the data I present to mean it’s perfectly safe to consume, say, 25% (or more) of total calories from SFA. I realize I may have to turn in my keto-club card, but I am convinced that a subset of the population—I don’t know how large or small, because my “N” is too small—are not better served by mainlining SFA, even in the complete absence of carbohydrates (i.e., nutritional ketosis).  Let me repeat this point: I have seen enough patients whose biomarkers go to hell in a hand basket when they ingest very high amounts of SFA. This leads me to believe some people are not genetically equipped to thrive in prolonged nutritional ketosis.

In one particularly interesting case, a patient in self-prescribed nutritional ketosis presented to me with an LDL-P of more than 3500 nmol/L1i.e., more particles than could be measured by the NMR machine so the report simply said “>3,500 nmol/L”. despite feeling, performing, and looking great. Based on his through-the-roof desmosterol and cholanstanol levels, and a curb-side consult from the Godfather- I mean Dr. Tom Dayspring, I decided to try an experiment. You see, the logical thing to do in this setting would have been to start two drugs immediately (a potent statin to address the hypersynthesis and ezetimibe to address the hyperabsorption) or tell him to abandon ketosis altogether. But this patient was adamant about staying in ketosis given the other benefits, though obviously worried about the long-term coronary implications. So, we agreed that for a 3 month trial period he would reduce SFA to an average of 25 g/day (vs. about 75 to 100 g/day) and make up the difference with monounsaturated fat (MUFA).2We also reduced his omega-3 PUFA given very high RBC EPA and DHA levels.

So, on balance, he consumed about the same number of calories and even total quantity of fat, but his distribution of fat intake changed and he heavily swapped out SFA for MUFA.

The result?

His LDL-P fell from >3,500 nmol/L to about 1,300 nmol/L (about 55th percentile), and his CRP fell from 2.9 mg/L to <0.3 mg/L (and for the lipoprotein cognoscenti, both desmosterol and cholanstanol fell).

Pretty cool, huh? So, my point is this: while I believe the population-based guidelines for SFA are not supported by a standard of science I consider acceptable, it does not imply I believe SFA is uniformly safe at all levels for all individuals.

Some of you may be wondering about me. It turns out I’m in the group (recall: I have no idea how large or small this group is) that seems to do well—at least by the tools we have available to assess risk—with large amounts of SFA in my diet, if and when I elect to. Even when I was in ketosis, eating 4,000 kcal/day (literally getting 40 to 45% of my calories from SFA alone) my biomarkers—cardiovascular, insulin resistance, inflammation—were excellent. Better than they ever were or even are today. Though, my point still stands: there are some people who do not appear able to safely consume massive amounts of SFA.

One last point I’ll make on this highly charged topic. I realize there is a contingent within the LCHF community who argue that traditional biomarkers of coronary risk—such as LDL-C or its superior cousin LDL-P—“don’t matter” if one is on a low carb or ketogenic diet. Maybe they are right. I guess time will tell. But I am not convinced, at least not yet.  As a doctor I can’t look a patient in the eye and tell them a sky-high LDL-P is ok because they don’t eat carbohydrates. So if you’re following such a diet, and your LDL-P goes through the roof, I’d urge you to consider a variation of the diet.

(Note: If you post your NMR results, please understand I will not comment on them.)

Talk 2: It was the best of times, it was the worst of times—the tale of the U.S. healthcare system


This presentation has nothing to do with nutrition but is, nevertheless, a topic I’m pretty obsessed with: how do we achieve cost containment on healthcare in the United States? (Sorry non-U.S. readers, but we have a bigger problem right now, so I’m focusing on ours over yours!)

This is a pretty controversial topic, so before you jump down my throat, try to sit through the entire talk, especially the parts where I frame the question as one of optimization. Most problems that have been heavily politicized suffer a common problem: they fail to distinguish between what is desirable in a resource unconstrained world (e.g., free health care for everyone that provides perfect care) and what is plausible the real world (e.g., some combination of features, but not 5 starts across the board).

Hope you enjoy the departure from the usual topics.

Pi Day

The math geeks in the audience will appreciate that yesterday, March 14, 2015, represented a very special variant of pi day. Normally, March 14 represents pi to 3 significant digits, namely, 3, 1, and 4 (i.e., 3.14). Yesterday, however, being the pi day in 2015, was especially cute, because it advanced two more significant digits, 1 and 5, via the year (i.e., 3.1415). If you’re a watch geek, in addition to being a math geek–yes, I realize this is not a huge club–the beauty of a perpetual calendar (a type of watch that shows time, month, date, and year inclusive of leap years), made it a really fun day! Why? Because at 9:26 and 54 seconds you found yourself at the following place in time: the 3rd month, 14th day, 15th year (of this century), 9th hour, 26th minute, and 54th second, that is, 3.141592654–pi to 10 significant digits!

After capturing this wonderful moment in time, I sent the picture, below, to my watch mentor (also a math geek; yes I just wrote the words “watch” and “mentor” next to each other). He loved it, but his response was priceless: “Peter, don’t ever show this to any woman you have the slightest interest in….check that, don’t show it to any woman period. Pretty cool though. You are right. I dig it.”

Good thing my days of trying to impress the ladies are far in the rear view mirror.

Parting shot: I did a follow up podcast with Tim Ferriss a few weeks ago. It’s episode #65 which is available on iTunes. This was my first time doing the strange format of just talking by myself. Feedback appreciated if this should morph into something I do quasi-regularly on the blog.


Pi on abstract background with about 3500 decimal digits by Nicolo Canali De Rossi is licensed under CC by 2.0

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  • Marc

    “Parting shot: I did a follow up podcast with Tim a few weeks ago. It’s episode #65 which is available on iTunes. This was my first time doing the strange format of just talking by myself. Feedback appreciated if this should morph into something I do quasi-regularly on the blog”

    It was a great podcast, I could have listened to more :).

    Could you discuss the topic of PCOS and oestrogen and the effects of diet/exercise in the next podcast?

    • I may have to do that, Marc.

    • Amanda

      I’d really like to hear about oestrogen/diet/exercise too, as well as any thoughts you have on fibromyalgia and diet/exercise. I’m halfway through epp #65 and am really enjoying it.

    • Neil Cooper

      I recently read that Attia Medical LLC is now in NYC. Where? How do I get in touch to perhaps schedule an appointment? Phone number, email address?
      You may recall tyhat we spoke some time ago, but I was reluctant to make the trip to San Diego.

  • Jim

    All things associated with nutrition seem enormously complicated to me. At the same time, I can’t help but think the answer to the million dollar question is right in front of my nose but I can’t see it. Spent much time researching different cultures looking for consistencies in diet. Lived with the Eskimos for a period of time. It seems to me, given the exact same inputs, under the same conditions, the results should always be consistent. However, two different people, given the same diet, do have very different responses. Furthermore, a single individual, consuming the exact same foods at two different times, also seem to have very different responses. It seems a somewhat logical(superficial) conclusion would be that diet does not relate. My only thought is that the conditions cannot be the same and therefore are not understood.

    Putting it in my own simplistic way, the y-axis would be the measure of health and the x-axis would be either different people, or the same individual, at a different time. If the inputs are equal and the results are different, the conditions are not understood. The million dollar questions, what is it? Ever changing genetic mutations? Off into the weeds, why does rapamycin appear to effect aging? Is it simply insulin response?

    • Nicky Hansard

      Honestly I think it’s pretty simple:

      Don’t eat processed food, don’t eat grains (except rice or similar products like oats), don’t eat dairy, minimise simple carbohydrates, minimise salt . Broken down a typical day could look like this:

      Breakfast – scrambled eggs with bacon or eggs, bacon, tomato or bacon/tomato/onion/egg omelette or oats with a dash of honey etc etc

      Lunch – fried rice with vegetables and egg or vegetable/chicken soup or meat with vegetables etc etc

      Dinner – vegetables and meat or a roast or rice and chicken or offal and rice stir fry or fish and rice etc etc

      Snacks – piece of fruit, handful of nuts, tuna etc etc

      Virtually all these things are simple to make. Some people don’t need to cut certain foods out of their diet and could thrive on nothing but salt, dairy, sugar and wheat bix but I think it’s highly unlikely that ANYBODY could eat the way I outlined and become obese, develop diabetes and similar diseases, nutritional deficiencies or intestinal issues. I reccomended avoiding grains and dairy because in my opinion, the evidence is pretty clear they are bad for lots of people and can be easily replaced with foods that are unarguably good for virtually everyone. I truly think the entire issue is being over complicated. Don’t get me wrong, sites like this are a necessity and the work Peter does is great to find out the body works.

    • Nicky Hansard

      Also I forgot to mention a couple of things:

      Offal meats contain more vitamins/minerals than any vegetable/fruit/grain/dairy product and they are easily digestible. So while many fruits/vegetables contain other beneficial substances, they are NOT neccesary to avoid nutritional deficiencies.

      Also intermediate fasting seems to be beneficial for humans e.g. only eat between 12:00-8:00 each day. It increases insulin sensitivity and seems to be beneficial for how the body utilises nutrients.

      Chronically raised insulin levels are apparently at the heart of many modern diseases. Directly caused by simple carbohydrates, usually in the form of processed foods.

      Chronic systemic inflammation also seems to be at the heart of many modern diseases. Evidence points to grains/dairy being inflammatory in the human system, as well as raised inaulin levels being inflammatory.

    • jw

      Not sure about that rice advice. Also, it is LCHF, and getting enough fat in a low-fat world is actually sometimes a challenge.

    • Nicky Hansard

      @JW I personally think rice is one of the best carbohydrates. Everybody is different and some people might need to remove essentially all carbs from their diet (including rice/oats). It’s just that I’ve never heard of rice causing a problem for people. Also I know this site is LCHF focused but I think the average person could follow what I outlined reasonably easily and not feel left out when having dinner with friends or what have you. I still think personally LCHF is the way to go but we have to be realistic.

    • Su-Chong Lim

      Sorry if I clicked the wrong “reply” button, but I had to address Nicky’s perception that rice is somehow OK whereas other carbohydrates are bad. Years ago I might have agreed with you. I am Chinese, and I seemed to have a disproportionate number of Asians among my patient population. As they and I aged together, I saw a greater and greater number of Asian patients with Type 2 Diabetes, a phenomenon I had not seen in my younger clinical experience. I’m not talking about the South Asian population (Indian and Pakistani genetics) whose incidence of Metabolic Syndrome, T2D, Cardiovascular Disease is quite well known. I’m talking about Chinese immigrants from Singapore, Malaysia, Indonesia, Hong Kong, China, and immigrants from the Phillippines, Indo-China, Japan, Korea and Thailand, and even their children. At the time (shame on me — but I graduated in 1972, and that was the underlying dietary message I learned), I blamed the high saturated fat and protein diet that they could now afford in the rich new world they emigrated into. My understanding now is that it was the carbohydrates that undid them. And what carbohydrates would it be for them? Well, certainly there was wheat in some of their noodles; and certainly there is too much unprocessed food and sugar in the easy packaged stuff you can get at supermarkets; but the overwhelming CHO in this population was Rice. Plain old Rice.

  • Please tell your friend that intelligent women do exist, and that some of us think that watch photo is the coolest thing, ever!

    • Ha ha! Good to know. I think the point he was probably making was less about intelligence and more about the narrow, narrow intersection of math and watch fanaticism in those with two X chromosomes.

    • NS

      I clicked the wrong “reply” button, meant to post it here.

      Same mentality that had Barbie saying: “Math is Hard,” “Let’s go shopping”.
      Sorry Peter, there’s no excuse for his comment.

    • NS

      Oh and one other thing. You should be aware that body image challenges aren’t the only way to destroy girls’ esteem, challenges regarding girls’ (women’s) mental abilities are equally destructive.

    • NS

      Oh and a third thing: I’m totally with Laura Jaymes, your picture of the ? watch is so totally cool!

    • Jane

      I dig it too.

      But the second point NS made is also very very important!!!! I am not sure my daughter understood how brilliant I always knew she was.

      Also, her best friend tried to schedule her own wedding at the local courthouse to coincide with the exact time on your watch!

    • b2curious

      I second your statement Laura. I think it’s majorly cool.

      And Peter, I figure there is a “narrow, narrow intersection of math and watch fanaticism” in the general population as a whole, regardless of gender. Oh, and I think that laughing out loud in response to what your daughter told you was absolutely the correct response. It helps bring home the point that the comment was WAY off base. And you got to help your daughter figure out how to deal with her own feelings when people say hurtful things that may or may not be true.

    • webgrrrl

      Someone might want to tell Attia’s pal that the current Fields’ medalist is a . . . a woman. He’d might enjoy getting used to it. 😉

      • I think he was more speaking about the dearth of ladies who dig watches with complicated movements like PCs…

  • DrEricDO

    Great follow up r.e. talk 1. I do think as physicians we have to be very cognizant of the reality that not every patient will fit into the ‘box” we would like them to fit in. Playing with the ratios of MUFA to SFA is a great place to start instead of jumping straight to meds when LDL-P is heading in the wrong direction.

    Did you see the Seventh Day Adventist’s most recent study? I had a good laugh, once again, how the media presents such studies. Supposedly, the study shows a lower reduction in colon cancer if you are a pescovegetarian. Good news for those of us who eat fish!

    When looking at the study and comparing to the general population the vegetarians have basically the same colon cancer risk as everyone else according to the CDC’s cancer statistics (60 per 100,000 people/year=4.5 life time risk of colo-rectal cancer which is the same for the vegan folks! Not reported though!). Very small benefit in the OBSERVATIONAL study (not a good type of study imho!) to those that ate animal fat in the form of fish though.

    Still, look at the real numbers in the study though. Out of 77,?659 people in the study over 7.3 years only 490 patients got colon-rectal cancer. So what is the real risk of colo-rectal cancer over a 7.3 year time frame? 490 over 77?659 = 99.4 % chance of not getting colo-rectal cancer in 7.3 years! Sorry, I’m not changing my diet to pescovegetarian to “decrease my risk”. Silliness! More ammo in my opinion for fat and animal protein consumers like me: animal protein and fat will not give you cancer!

    We celebrated Pi Day yesterday as well by cooking a low carb pumpkin pie! The kids loved it.

  • Dan Walker

    You know, ultimately right, wrong, or anywhere in between (and I know I mention this a lot here) you always give us as much thoughtful insight and knowledge as you possibly have time for, which is something we could certainly use as much of as we can get in today’s world, and I know there are a whole bunch of us who really appreciate it.

    I still do not understand how some people really have enough time on their hands, and they honestly somehow believe it is worthwhile, to try and tear somebody down out on the internet. Presenting an opposing perspective and trying to back it up with what evidence they have is one thing, but some people to just go to bizarre lengths to try and prove who is the biggest troll in the universe. I have a friend who is a very high profile video game designer and he has developed a skin made of exotic alloy with all the trolls that roll off of his back on an almost daily basis. Much of the time karma takes care of most that come after him, but every once in a while I’ll get to see him make use of his nearly surgical wit on twitter to take a few of them off at the knees. I hope I live to see the day when the greatest majority of people spend their time living a happier life and do their part to help us all move forward. I believe we are really going to need that if we are to advance much further than where we are now.

    For what it’s worth, in case somebody reading this is wondering about other people’s experience with designing their fat breakdown for a KD. I definitely feel like a bear in a hibernating torpor when I consume a particularly high SFA percentage. All I want to do is sit in front of the TV all day. I found that if I raised the percentage of MUFA much higher I felt a whole lot better and had better energy levels. I like the high end specialty olive oils and always try to buy the ones with the highest polyphenol counts but I often find them too robust for my palette so I tend to cut them with a high oleic sunflower oil which is nearly flavorless. Spectrum seems to be the easiest thing for me to get my hands on and their HO sunflower oil has a half a gram less of PUFA, per serving, than their high oleic safflower oil. At least according to their label anyway. I have not been able to find anything with a higher MUFA content than those 3 other than macadamia oil, which is interesting, but I like my macadamia nuts to taste like macadamia nuts and not very many other things. The oil tastes good but the flavor is very overpowering when combined with other foods and generally not very complementary to most foods. To me at least anyway. Kind of like virgin coconut oil. I like coconut but it just doesn’t go particularly well with many things you use oil for so if I use it I generally will use the refined oil as long as I can find an organic one that hasn’t been refined in a poor manner.

    Beautiful time piece BTW. I am as about as close to the epitome of a Myers-Briggs ISTP as you will find so I can fully appreciate some of the utterly mind boggling design and super intricate craftsmanship that goes into many luxury time pieces, but I oddly enough eschew them for utilitarian pieces that I can get caked in mud or take to the shallow bottom of the Gulf of Mexico. A Sinn U1 on a metal bracelet is going to be about as dressy as it gets for me.

    Thanks Peter!

    • Thanks, Dan. Despite being the poster child for ISTPs, somehow I find it in me to be obsessed with watches and pens…

  • Whitney

    I really appreciate your thoughts on SFA here. I’ve been skeptical of the whole bulletproof way of life, and I think your effort to spread the word that something that is good for one does not mean it is good for all is so wonderful. Scream it from the rooftops and great post.

    Also, side note, if that happened to my daughter I do not know how I would have reacted. Girls in particular can be so cruel. I think you handled it brilliantly, a girl’s confidence is the most gorgeous thing she can wear.

    • You said it… the cruelty is simply amazing to me. The best advice I was ever given about parenting is to show my vulnerability. Let my kids know I can be hurt, I can be sad, I can be afraid. Seems counter-intuitive, I know, but I’ve seen amazing results in the kids of my friends who have done this.

    • Jane

      I agree, Whitney!

      My poor mother and her friend were called “hippo” (her no doubt) and “pottamus” as children. Her self-confidence was damaged for life. (No doubt there were other causes as well.)
      She was a beautiful woman, but was always trying to lose weight. I remember the Metrecal drinks from the 60’s.

      As she aged, and she lost her appetite while her frontal lobe dementia progressed, she became very thin. Even though she was dying (something she may not have understood),, she was so glad to be slimming!

  • greensleeves

    So Peter for those of us who have our 23andMe results, what should we be looking for to see if we’re in this “replace with MUFA” group? Ty!

    • I’m not sure it’s something 23&me can assess. In my experiences (limited) it’s more empirical and based on the change in sterols.

    • Bill Vincent

      It’s certainly possible that SFA sensitivity could be a result of evolutionary DNA mutation(s) that first occurred in more recent times, much like lactose tolerance:
      Logically, any such mutation(s) would probably have arisen in a population where MUFA were heavily substituted for SFA. The Mediterranean region would be a likely suspect region, and perhaps more SFA-sensitive patients might be found there. DNA analysis would need to be conducted on a sufficient (?) number of patients with known SFA sensitivity before common mutation(s) could be identified. Finding the exact genetic marker(s) will be difficult, because most people with SFA sensitivity are probably have no awareness of it. Perhaps 23andMe might be able to provide some insight to your question, but I suspect the answer is unknowable at this time.

  • Milli

    I’m a Math teacher, and I was pretty excited about yesterday! 🙂

    Thanks for this post. I’ve been trying to work out a variation of LCHF that will work for me. I think I’m in the small percentage that can’t tolerate high amounts of SFA. My cholesterol was through the roof and my doctor freaked out, but I thought it was more tied to untreated hypothyroidism than to being in nutritional ketosis.

    Anyway, although I refuse statins and I’m on medication for the thyroid issues, I still felt like I needed to watch my SFA intake. This post was confirmation of that.

    So, thanks again for all you do. I direct everyone I know to this website all the time, and I tell them about NuSI and how excited I am about what will come from it.

    I’ve been reading for a year (although this is my first comment) and I am cured of PCOS now. I thank God, but I thank you too!!!

    P.s: you sound like a great father. My dad called me fat when I was 14! :p. So now I obsess about staying a size 4. Sad, but true.

    • Milli, so glad to hear about your PCOS story. I hope the SFA journey solves it self with some experimentation. Sorry to hear about your dad. I obsess over this a LOT. My daughter knows I avoid sugar. I explain it in terms of sugar’s effect on my performance, not my waistline.

  • Vance


    Do you have a link to the podcast?


  • Patrick Arnold

    Nice way you handled the situation with your daughter

    BTW your’e BALD!!

  • newbie

    Tim Ferris? Happy to look it up – just need to confirm the name. Thanks.

  • Mickey Goyal

    Dr. Attia, always insightful views on your blog. Many thanks for your views. Great story about your daughter – who I believe is the same age as mine 🙂

    I may be one of the “fundamentalist LCHF” this blog is meant for. I might have to try to cut down on SFA and replace it with MUFA to see how it impacts my LDL-P, which was rather high when I measured last year.

    On a side note, when do we see some results from NUSI start coming in?

    Mickey G

  • Sam


    Interesting comments on the podcast re Theranos and tests you recommend for longevity purposes. That said, I’ve been on a high-fat diet with seemingly good results for a few years now, but I’ve been scared to get blood work done, in part because intimidated and unsure what I should be asking my physician to test for. At this point is there a standardized set of blood tests that are easy to request from a new physician? Are physicians accustomed to being asked to do NMR testing? Are Wellness FX, SpectraCell, and similar companies useful in this context?


    • Docs are slowly getting more acquainted with NMR, but if they don’t know how to interpret and treat, they are not likely to order.

    • Colleen

      Be very specific with your doctor. My husband was, asking for the NMR, I can no longer recall all the details, but he was very specific when he asked the doctor whether she could get that test. She said yes and was so glad he was so interested/proactive re his health. When he got the results, it was not the NMR but only a calculated APO B.

  • Ash Simmonds

    This is a copy/pasta response I drunkenly made to Ivor Cummings (Cholesterol Conundrum/Fat Emporer Irish guy) on Bill Lagakos’s blog last year, which explains my (mis)understanding of the LDL-P situation:


    Ivor: “I am interested in locking down on particle number being directly causal as opposed to partially associative too”–

    Ash: Good luck with that, probably as misguided as the idea that cholesterol itself is evil.

    My current analogy* for particle number is one of traffic and roads. If the roads in your city are narrow torn up and potholed and poorly maintained and badly signed with shitty traffic flow and fuckwit drivers etc then the number of cars on it is a huge issue. You’ll get away with a small number of cars as when there’s the inevitble crash the ambulances/maintenance crews can get in and fix without much issue apart from little room on the shoulder. But if you have way too many cars there are more crashes, and subsequent pile-ups, and the emergency services either can’t get there to fix it in time OR they themselves become part of the pile-up.

    Then imagine a marble-smooth nice wide freeway, well maintained at the first sign of a pothole, traffic is well directed and flows like beer at Schutzenfest, and the drivers are a bunch of Canadians. Sure, the occasional crash happens, but emergency services can get there quickly and easily and they have plenty of room to deal with the situation. In this case it doesn’t really matter if there’s only several hundred cars, or a couple thousand.

    So yeah to me particle number is strictly correlative, because discordance. You simply can’t find near 100% of the time it being there. High particle number in a super inflammatory environment – MURDER ON THE DANCE FLOOR. High particle number in a well oiled machine – STAYIN’ ALIVE.

    *subject to change if I hear better :p


    Keen to hear if I’m on the right track or full of crap.

    • I don’t know. It’s not my belief.

    • Michael Trumper

      Nice analogy, but you obviously have never driven in Vancouver 🙂

  • Norm

    Hi Peter,

    Thanks for another great post and the podcast.

    1. Among the signals you mentioned about the unsuitability of KD for an individual, could we add that drop in libido, drop in basal tempaerature to 96.8 and deterioration in the quality of sleep and mood for an individual even after being fully adapted to KD might also suggest that KD is perhaps not suitable?

    2. You mentioned caloric restriction in the podcast in the context of post exercise carbs/whey, do you deliberately restrict calories in your diet? If so, how do you achieve this? Is it via IF?


  • steve

    Hi Peter,
    Always enjoy your thoughts and articles. Thanks for taking the time to write them. I am wondering if you have looked into the link between iron and LDL oxidation. I dropped my LDL from over 200 to below 100 after reducing my iron levels, which were high enough to induce inflammation as measured by UIBC and TIBC tests. I also did not dramatically reduce my fat consumption though I did rotate from saturated to more monosaturated fats. However, I still eat eggs every day and only buy whole milk yogurt and cheese. So I still get a decent does of saturated fats. I’m wondering if saturated fat is only a necessary (but not sufficient) condition and that inflammation must be present to throw things out of whack. Varying levels of iron loads across people can also explain the ability to handle saturated fat, though I am just hypothesizing.

    • Interesting. How is it possible to know if the change was solely due to reducing iron levels vs. some other change that accompanied this reduction?

    • steve

      There was no reply link to your response to my post so I have to reply back to myself. Regarding iron, I do not know that the change is solely due to reducing iron levels vs some other change. I posed it as a hypothesis and was wondering about your thoughts. But I am a fairly stringent diet self-experimenter and that was the single biggest change I made between blood tests.

      I had experimented with reducing saturated fat and increasing carbs two blood tests ago and while they improved things a little (LDL-C dropped from 265 to 205), this latest drop was huge (205 to 89). My saturated fat decrease and carb increase in my latest blood test was only marginal. So I suspect it was the iron, though I can’t say for certain.

      Also I had posted my numbers on Paul Jaminet’s forum and he was worried that I now have anemia due to my low LDL. He didn’t think the carb increase could have done it. So he thinks there is a link between LDL and iron though he did not go into details.

    • Dan

      This is interesting. I am homozygous for the C282Y mutation on the HFE gene and suffer from haemochromatosis. Fortunately I found out about it from 23andme and have confirmed via multiple blood tests and consultation with a haematologist. I just had my lipids re-done for the first time in 2 years and my LDL has gone from 40 to 104 (LDL-P was ~1400 but I didn’t have a previous number) however there are far too many other variables (it was 2 years ago) for me to be able to pin it on the increase in my transferrin saturation (~70%->99%). I have recently (about 2.5 weeks ago) massively increased my fat intake as part of a ketogenic diet and 2 weeks ago I ran a 100 mile ultra so many of my blood markers are currently a bit of a mess (thyroid, CRP etc).

      I would be interested in any further info anyone has on iron and its affects on lipid profiles. I will certainly be lowering my iron levels back into normal range and making an effort to move to a low iron diet so that I can manage things without treatment. I will also be getting all of the tests re-done in about 2-3 months but I would just be guessing if I said that any change was caused by the iron.

      One thing is for sure, everything I read, and everything my haematologist tells me is that even slightly increased iron levels are being shown to have unpleasant effects so I think I need to be more sensible in my diet and keep them low, especially as I have been lucky to find out about the condition before it has any nasty side effects.

      Thanks for the fantastic blog Peter. I love what you are doing at Nusi and find the depth and detail to all of your articles to be amazing. There are too many people writing blogs about keto that basically just say “eat lots of butter and cream” and tell people to ignore their LDL-P numbers…I find that reckless so I am happy you are willing to challenge the keto lobby occasionally. This is also one of the only blogs that has good info for athletes which I have found invaluable. I have been reading your blog repeatedly for the past 2 months and just waiting for a good time (post races) to attempt my keto-adaption. My main reason for trying this is that I like the idea of being metabolically flexible in long endurance events and I am really not convinced that dumping 50+ gels into your body in a 24 hour period is good for you long term…

      Thanks again.


  • Tim C

    “are not better served by mainlining SFA, even in the complete absence of carbohydrates ”

    I’ve recently come to the conclusion that a ketogenic diet is not for me. I still limit my carbs, especially sucrose and HFCS, but I find myself feeling much better with the occassional potato and fruit, and I also find myself feeling better with more protein than a ketogenic diet allows.

    The point you’ve made, more than a couple times on your blog, is that needs vary by individual. I think that’s been my biggest epiphany over the past 6 months or so

    “such as LDL-C or its superior cousin LDL-P—’don’t matter’…Maybe they are right. I guess time will tell. But I am not convinced, at least not yet.”. I got the impression from your Tim Ferris podcast a few days ago that you’re even less tentative than that. It will be interesting to see what the data tells us, now that a lot of people are shifting focus to LDL-P, and are giving more skepticism to the lipid hypothesis.

    • Jane

      See case 291 on Dr. Dayspring’s website, the Lipid Academy.

      LDL-p matters!

  • Michael

    Hey Peter –
    I am a primary doc practicing 30 yrs now . Regarding cost containment – and advising folks on exercise – do you have an opinion on the McGuff method vs lower intensity methods? I ask only about strength training – another words I am accepting the hypothesis that strength training for the populace will add more fitness benefit than “cardio” .
    I know that strength training would not be a “normal” issue to bring up in discussing health care cost containment but I do agree with DOug McGuff . He was asked what one thing anyone can do to improve their health , and his answer was strength training .
    Enjoyed the monologue podcast. Keep up the good work.
    FWIW, I am a parent also and did show my kids my vulnerable side at times. Good job .

    • Yes, I’m a proponent of Doug’s work and methods. If you can only spend an hour per week exercising, there is little I can think of that gets more bang for $.

  • Anthony Spadafora

    After reading this I had to ask myself,” Who dislikes Peter Attia” after all you are a very personable guy. So I did some searching on You tube and found the Australian vegan guy who wants to race you. lol . There is also a young girl that I follow, Kendall Jones. She is a big game hunter and is attacked constantly by vegans and peta. She is quite good at rebuffing their insults. Thought you might use some of her ideas. Keep up the great work!

    • Impressive guy, huh?

    • Christopher Grove

      I KNOW, EH!!??
      Yes, that 30 bananas, Rider guy gets on my nerves too, so Peter can always count on you and me defending him from too many bananas!

  • Lydee Scudder

    I find it particularly cool that pi day was (and always is, at least in the US) Einstein’s birthday.

  • Mario Vachon

    Hi Peter. I love your work as I’m sure everyone here does. This is unrelated to your current post but I was wondering when any results might be available on the first trials being done at NUSI?

    • Ping NuSI site. I’m trying to keep this to blog stuff.

  • Conni

    Peter, you said: my biomarkers—cardiovascular, insulin resistance, inflammation—were excellent.

    I have finally found a GP who is more or less willing to accept my ketosis diet, but I don’t know what tests to ask for to find out how my biomarkers are doing. My blood work is excellent (high HDL, low Triglycerides, big fat fluffy LDL), but how should she test for insulin resistance? Inflammation? What else?

    I went through a tough time, ate carbs and gained ten pounds, and now back into ketosis for two solid months I can’t make it budge. I’m willing to make adjustments, add MUFA, lower SFA, maybe even increase carbs… but what tests should I request to figure out my individual needs?

    Thought maybe others would find the info useful also.

  • BobM

    What was he eating to cause a high SFA content? Most meat has more MUFA than SFA (lard is more MUFA than SFA). Also, even olive oil has SFA in it. What did he drop and also what did he begin eating?

    I was drinking bulletproof coffee/tea, but stopped. I stopped because of calories not SFA though. I still drink it every once in a while. For me, I’ve always had low (total) cholesterol and low HDL. Not sure why. Nothing seems to change these. We’ll see after another year of low carb/high fat. I do not get an LDL-P test done, though. I’m not sure where to even get that test done. Instead, I’ve been getting the VAP cholesterol profile done, and that I’ve had to pay for myself (my doctor refused to order it and also Hemoglobin A1C — 5.4 — and vitamin D) I have a Pattern A/B but close to Pattern A.

  • Jayne

    Loved the podcast! Would love to hear more.

    Thank you so much for the SFA comments. My LDL-P jumped too, I’m not in ketosis -70g carbs/day, just low enough carb to keep glucose in check. Boy did I get flack about replacing some SFA with MUFA in when I mentioned it on a forum. Anyway I don’t want my LDL-P to be high, so I went back to olive oil while keeping in some SFA. We’ll see this week if it worked! If not- now I know I can try even more MUFA and less SFA!

    Love your watch.

    And thanks again for this post.

  • Christopher Grove

    Firstly, Peter, in case the school bullies pick on you… YOU’RE NOT FAT!

    Secondly, that item re SFA is quite the ongoing point of fascination for me. Despite individuals doing well or not well on SFAs, I guess it is safe to say that one can’t go wrong with doing lots of MUFAs… swapping out that one inch layer of fat on my steaks for more olive oil on my salads??? (Or can one???)

    I’ve been TRYING to stick to Dr. Terry Wahls’ (“The Wahl’s Protocol”) version of ketogenic by eating way more veggies than even the average Paleo advocate does (3 cups each day of leafy greens, 3 cups of coloured… <–I refuse to give up the "u" while living down here… veggies and 3-cups of sulphur-containing veggies) so it has been easier to do the swapping out of SFAs for MUFAs. But the question of safety has still always been on my mind.

  • Nancy

    Enjoy reading your thoughts very much. Buy was shocked by your friend’s comment re: Pi Day. My daughter and I (female) were both very excited by it! Interest in these things is definitely not restricted to men only!

    • I think his comment was more about watches and specifically PCs and pi day…

  • Josh

    The dollars at a recent high Peter, take the bet!

  • Leah

    I’d like to know what other tests you ran on the patient with the off the chart LDL-P number on NMR. Are there other inflammatory markers besides hsCRP that you looked at? And if the patient’s crp numbers been extremely low would you still have suggested reducing SFA intake? That is, what all went into your decision to make your recommendation? It would be interesting to know what LDL-P numbers people with familial hypercholestrolimia run, since some studies like the Utah Pedigree show normal life expectancies even with extremely high cholesterol, like 500-1000. Some people with FH die very early in 20’s, 30’s or 40’s. Other lives well into their 80’s. How can high cholestrol be a threat when younger, but not when older?

    • If I didn’t mention something it was either normal or pertinent to the discussion. This patient did not have FH based on earlier LDL-C and TC-C levels. He’d never had apoB or LDL-P checked, though.

    • Jane


      Any connection between either FH (familial hypercholesteronemia) or FDB (familial dysbetalipoproteinemia) and saturated fats vs monosaturated fats intake?
      What about AP0-E status?

      Isn’t coconut oil saturated? So, what do we cook with?

      Also, for those of us concerned with brain health (all of us!), what about cholesterol synthesis in the brain itself?
      What if levels of large particles (both) are high? In other words, if we have been following both the Taubes/Attia ideas and the Gardner & Westman research?

      Geez, we all need concierge doctors with your knowledge!

      • All great questions suitable for another podcast!

  • Yossi Mandel

    Try this:

    To me the stuff I’ve seen online about you has been laughable more than anything else, but I’m sure from your side occasionally something gets through the thick skin. And oh yes, I have unfond memories of the piss-and-vinegar days of the mid-90s internet. Thankfully we all wrote anonymously then, but them were some sharp words I was at the receiving end of… and gave some in return as well, regretfully. Lots of mistakes to learn from.

    Pi day was great. Low carb pie, of course.

    On the podcast, I was wondering what it would have sounded like if Tim had read the listener’s questions to you, making it more interview style instead of monologue. It was definitely a great way for you to present what you did in the past here on the blog, you could let yourself wander and talk without needing to worry about editing time and concise writing structure. Well, sort of concise. The concise we like – “long enough to cover the subject and short enough to be interesting.” If you do continue with podcasts on your own, and plan to do it more along the lines of your speeches and the blog, perhaps breaking it up into question and answer format or interview (of you) format might make it more interesting.

    • I much prefer Q&A, but Tim’s bandwidth is on par with mine…so the monologue leads to more frequent content. Anything to make this format less awkward is appreciated.

    • Yossi Mandel

      Hmmm. There are humorous ways to do it of course, but serious ways don’t come easily to mind that wouldn’t take time to set up – bumper music, sound effects, etc.

      But having Yoda read the questions would be funny. Or your daughter reading them.

    • Yossi Mandel

      The “Attia, Père et Fille” Podcast.

  • Mike Hurley

    That looks like a $10,000 watch!

  • John U

    Hi Dr. Attia. I do love your work and your site, and this is the first time I need to get some clarification.

    You said: “So, my point is this: while I believe the population-based guidelines for SFA are not supported by a standard of science I consider acceptable, it does not imply I believe SFA is uniformly safe at all levels for all individuals”.

    This statement appears to be based on your observations of various patients who showed very high levels of LDL-P and also high CRP, and other indicators while eating a high SPA diet.

    However, is there any reason to believe that high levels of LDL-P (especially if the particles are mostly pattern A) are indicative of a problem? After all, no one has yet published a comprehensive theory of what causes heart disease which has gained traction, so no one really knows if there is a plausible connection between high levels of LDL-P and heart disease. In other words, even if the levels are high, is there any science to suggest that this is bad? Is it only observational data which is leading to this caution exhibited in your statement above? Could there be other factors which also changed when you switched the diet to more MUFA and less SFA? And, since these LDL levels are supposedly indicators of the onset or of the existence of heart disease, is it reasonable to believe that such conditions have been corrected in just 3 months?

    I am wondering where the science is in all of this.

    • Great question, but one I’ve addressed at enormous length in responses to previous questions during the cholesterol series (back when I had time for one hour responses). Anything shy of that is just being glib and unhelpful on this topic.

  • John Wilson


    Regarding the patient on Nutritional Ketosis that benefitted from reducing portion of saturated fat, you didn’t tell us what happened to his triglycerides! Is this information available? BTW, thanks for another great post.

    • Started relatively low (76 mg/dL) and went lower (62 mg/dL).

  • Brad

    What sources of MUFA did this patient use in place of his/her SFA intake?

    • Macs and OO mostly.

    • George


      OK, olive oil and macadamia nuts. But do you think one could also use high oleic sunflower/safflower oil? And what about coconut oil–is that in some special category that doesn’t really effectively count as an SFA in the context of your article above?

  • Birgit

    I just listened to the talk about healthcare and love it. Will pass it on on social media. Just wish it had been available earlier.

  • Mike Goldbarg

    Peter, each time i receive notification of a new blog post, a sense of exciting anticipation rises until i see once again it is not the promised Part 10 of the your cholesteral saga. Not saying the other posts are not fun to read, but c’mon now, you did promise …

    • Hey, I sort of gave you one of the important themes of Part X in this post! In fact, I should rename this post “Part X.”

    • Jane

      But Peter,
      So much of it is anecdotal!

  • Joshua Titus

    Great podcast (both of them), definitely loaded with information and worth the listen. I will say, I prefer the banter between you and Tim better, as this can lead off on other interesting tangents, but a monologue is clearly more effective a purely answering questions. Thanks either way, always awesome!

    • Yes, I prefer the banter too. At least that way I get something out of it! The monologue is pure pain.

  • BobM

    My problem with LDL-P is that it’s being correlated with heart disease. As such, how do we know it’s not a correlation like the many other correlations (LDL, total cholesterol, you name it) that have come and gone in the past? So many of them have failed. Until there are repeated studies indicating that LDL-P has a correlation with heart disease and there are studies indicating that lowering LDL-P (preferably through non-drug techniques) has a positive benefit, I’m loathe to place much emphasis on it.

    I also believe we don’t know much at all about what causes heart disease. Personally, I’m in the Malcolm Kendrik camp with this one:

  • Deb

    I am one of those whose LDL went through the roof when I started a high fat, low carb , ketogenic diet. (I love my bulletproof coffee:>) I did have an NMR and my particle number is high but the size is large. Since my other markers are good I have not altered anything. I have been thinking of having the test that would tell me if I have any signs of plaque.

    A ketogenic diet works really good for me so I would like to continue but not at the risk of damaging my health!! I like the idea of lowering SFA and increasing MUFA but I don’t know which MUFA’s are the best besides Olive oil and macs, I don’t like Olive Oil but could tolerate it I guess. I do have some flavored. I like Macadamia nut oil and coconut oil, MCT oil.. I eat an avacado every day.

    I could use some ideas on what fats to reduce (is butter the culprite?) and what Mufa’s to add into my diet.
    And, what do you think of lard? I got a jar from a friend for Christmas:>) I

  • Mike Goldbarg

    Peter this is how you you left us hanging at ht eend of chapter 9
    “I would like to address one additional topic in this series before wrapping it up – the role of pharmacologic intervention in the treatment and prevention of atherosclerotic disease, so please hold off on questions pertaining to this topic for now.”
    Missed any reference to pharmacologic intervention here.

  • Tricia McVey

    Regarding talk one. Is there a way to know if your in the group that doesn’t tolerate saturated fat before you get your first lipid panel done as an adult, carbs or no carbs?

    Also, kids sure can be on the mean side and it seems like the girls get a head start with it. Lots of self esteem talks with my daughter when she was that age as well, and into Junior High. Paid off by the time high school came around she handles it much better. My son hasn’t had the same experience fortunately. Definitely some differences between boys and girls growing up!

    Thanks Peter!

    • It’s really only something one can tell with trial and error. Ideally, at least in my experience, it requires that I can see a change in NMR profile, plus sterol profile.

  • Andy Chow

    Looking for some clarification on this part of the post:

    “I have seen enough patients whose biomarkers go to hell in a hand basket when they ingest very high amounts of SFA. This leads me to believe some people are genetically equipped to thrive in prolonged nutritional ketosis.”

    Does this mean that you believe people whose biomarkers go to hell with high SFA thrive in prolonged nutritional ketosis? If so, why?

    • Good catch, Andy. Typo now corrected. I suspect there are many people–despite all the substitutions available–who are not best served by a KD.

  • KeanC

    You mentioned in your TF podcast that you take Berberine as a daily supplement. The positive effects through reduction of IGF-1 and LDL-P are compelling however, some studies show that it inhibits DPP IV whilst raising GLP-1, both possibly cancer promoting. Can you share your thoughts on the risks associated with supplementing Berberine, how you weigh up the benefits against the risks and what you may be doing to mitigate those risks?


    • I’m not sure I buy the logic that DPP IV inhibition and/or GLP-1 agonism cause cancer. If they do, the effect must be VERY small, given how many patients take potent drugs that do both, right?

    • Martin

      Peter, could you point to any studies that explain how berberine works (re the aforementioned IGF-1 and LDL-P reduction)? Simple statements that I’ve come across simply say that it “stimulates insulin”, which is probably incorrect. If true, though, this effect would not be very desirable, would it?

      • Berberine inhibits PCSK9. In a subset of the population–no on really knows, but estimates are 10-15%–PCSK9 is overexpressed. Ergo blocking PCSK9 in these patients lowers LDL-P. Atherotech has a test for PCSK9 expression (not gene).

    • Martin

      OK, found this site which seems to document it pretty well:

  • Tyler

    Dr. Attia,

    I’ve recently began introduced to you through Tim Ferriss’ podcast and now I’ve been rummaging through your website. Great information! As a 4th year medical student about to start a Family Medicine residency–do you have any advice on how to begin to structure my career to become more involved in this kind of medicine? Would you call what you do functional medicine? What does your practice look like?


  • Dan

    I’m new to your blog – thanks for your posts! Over the last six months I’ve lost 30 lbs on LCHF and am now a much healthier BMI 25, and still working at it.

    I’m sorry if you’ve already posted this and I don’t see it, but do you have a list of recommended blood tests to check? I gather the NMR lipoprotein panel – which others?



  • KC

    Very well written, but the hi-light for me was seeing your Jaeger perpetual calendar!
    Great taste in watches.

    • I’m just obsessed with JLC’s…

    • Naren

      Does that mean you have other JLCs in addition to this PC. Any Reversos?

      If you ever decide to share, I’m very excited to hear what else you wear. So far the count is SS Daytona, Speedy Pro, JLC PC…

      Really enjoy your stuff, Peter.

      • Ahhhh, a fellow watch idiot I mean lover 🙂
        Next up is reverso 2-time zone or Speedy grey side of the moon.

  • Ann M

    I went paleo 3 years ago. I’d had advanced testing prior and my ldl-p hovered around 900. On paleo, it doubled to 1800. My cardiologist consulted with the Godfather at my request because I literally had resolved every niggling health condition, acne, weight, mood, allergies… you know the drill. Anyway, statin/zetia combo suggested and so I went on the hunt for answers without those meds. A functional medicine doctor suggested low fat, high protein, more carbs. I felt terrible, the best description is I felt hypoglycemic, constantly “hangry” & nothing tasted good. Then I signed up to be an NTC through NTA. My latest experimentation from those learnings is to play around with my fat absorption. While I didn’t score high at all on my fatty acid balance, fats are the issue at hand… so I started working on digestion, especially on the front end of the process. I relax before I eat. HCl supplementation & limited liquids with meals. I’m kind to my liver through lifestyle and take supportive supplements every now and again. Mainly though, I take supplements designed to help the gallbladder, namely beta-tcp from Biotics (beet juice, taurine, vit c, and pancrelipase) and phoshatidylcholine. I also take a B supplement that focuses on riboflavin but has the usual mix of the other B’s. One month in and I’m at 1300 ldl-p.

    My lp(a) is also lower but still wicked high. My lp-pla2 is high (but lower) and my hs-crp had always been super low. I hyperabsorb those plant sterols too. All other markers score optimal on hdl labs advanced testing.

    You’ve given me another angle to play around with… I favor SFA’s (so tasty) but I can easily change the mix to sku higher to the MUFA’s! As always, thanks for the info.

  • JJ Bell

    Another great post Peter, many thanks!

    Although my first reaction would be to want to punch anyone vocally criticising someone as well considered, reasonable and open-minded as yourself, divisiveness seems to be necessary to be noticed ‘these days’.

    I know you can take it and maybe is a good opportunity for your daughter to pick up some of her Dad’s grit an an early age.

    Appreciate the context given for nutritional tinkerings, inspired me to save some pennies to test my own numbers in (felt amazing mentally since upping SFA over past couple of years and switching from living on breakfast cereal and apples diet to similar macro mix to yourself but would be good to know if any unfelt effects under the hood).

    Thanks again


    ps Stuff with Tim = gold. Do more please!

    • Thanks, JJ. I’m the question list from folks was long and I only got through 10% of it, so I’m sure there will be more.

  • Chris

    You know Peter, books like Carol’s are the kind of books I was searching for yesterday. Something along the lines of ‘how to create a mind’…Thanks for the recommendation.

    Do not worry about people who hate, focus on those who listen.

  • Conni

    Hello, I’m going to ask again, because even if Peter doesn’t answer, I think others here may know and respond.

    My question is, exactly what tests should a low carber ask for, to determine their “biomarkers”?

    For instance, what test determines the level of insulin resistance? Usually we are told “yes you are diabetic” or “no you are not”, rather than some level on a scale of resistant.

    What is the test for inflammation?

    What specific blood work should we request?

    I understand that unless there are medical reasons or symptoms, it would not be necessary to do every test available. But a quick rundown of the tests that we should get annually would be nice. I had to jump through hoops to get my GP to test the size of my LDL, as the solo number is useless. It would be nice to know what else to ask for.

    Thank you.

    • Chris

      Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and plasma viscosity (PV).
      A good empirical check is not having sore (stiff and painful) muscles the day or two after exercise that you are conditioned to. If you do then there is probably underlying chronic inflammation!

    • Yossi Mandel

      The widely performed test for IR is the oral glucose tolerance test, especially if they draw blood for insulin as well and not just glucose.. The more accurate test performed under lab conditions is the euglycemic clamp. For the diabetes symptom of IR, the hba1c performed every 3 months is the best indication of how under control you have your blood sugar fluctuations.

      For LDL, best look for a lipidologist as opposed to your GP.

      Unless you’re diagnosed with an illness, tests depend on what you what to accomplish and what you are worried about. Share that, and people can respond with appropriate tests. For example, is your goal weight loss? Dr. Attia recommended the DEXA scan no more than every 3 months to get a precise picture of fat loss vs body weight loss and more details.

    • Conni

      Chris, I googled your tests and see that they are all related to inflammation. I do not think I have any issues with inflammation, and your tip about the empirical check is very helpful. Thank you.

      Yossi, I also googled the oral glucose tolerance test. It says that you have to eat 150 grams of carbs for three days and then go in for testing. Since I am on a ketogenic diet, doing that would shoot me straight out of ketosis and make me feel physically crummy, and it’s not clear what the test would tell me. I am quite sure I am not diabetic or in danger of becoming diabetic since going low carb three+ years ago. The euglycemic clamp looks interesting, but it also looks like a diagnostic tool for diabetes, although I may not be understanding it clearly. That is a test I could certainly bring up with my doc.

      You’re probably right about the lipidologist, although my GP did finally agree to do the more comprehensive blood test.

      I’m confused about the DEXA scan, that looks like a scan for bone density, not fat loss, but I could be misunderstanding.

      What I’m trying to accomplish may be impossible, or I may not know enough to ask the right questions. I want to lose weight and then maintain that loss, while eating as many healthy carbs (whole foods, not processed foods) as I can, without having my weight be the only measure of what is safe to eat. I don’t know if I’m insulin resistant, but I do know that it takes a surprisingly small amount of carbs to make me swerve out of ketosis and start to gain weight. Anything over 20 carbs per meal and I get into trouble. Since my initial weight loss three years ago, my weight has been creeping up little by little, despite my best efforts, and I don’t know why. I recently had a leap upward in weight that was entirely my own fault, (stress related eating), but I have been solidly in ketosis for two months now and remain ten pounds overweight, the weight refuses to budge. Again, I don’t know why.

      Anyway, I’m grateful to both of you for responding to my post. Thank you.

    • webgrrrl

      Conni, if you’re a female over 35, your last 15 pounds are about your female hormone balance & cortisol – once everything else is dialed in. And the news about that 15’s gonna be bad unless you’re prepared for bio-identicals.

      Women aren’t men, but Peter rarely discusses the special needs of women; he may not be expert in them.

    • Conni

      Thanks webgrrrl. I’m about to turn 56, and am pre-menopausal (still!). Part of my drive to lose these ten pounds is that once I’m through menopause I know it will be even harder to lose any extra weight I’m carrying. My sister is sold on bioidenticals, they helped her with truly heinous PMS symptoms. I am less thrilled about messing with my natural hormones.

      I have cut down on calories and that seems to be helping. Based on my experience, I think the older we get, the more calories do matter. We don’t shed the excess calories as easily as when we’re younger. And I may have to come to grips with carrying excess weight due to reduced estrogen.

      Thanks much for your reply.

  • Vinayak

    Speaking of podcasts with Tim Ferriss, please do many more of them!

    • Colleen


  • Hank

    As a follower of your blog for the past 2 years, it’s been frustrating trying to get an NMR profile done. Per your blog, the NMR profile appears to be key to understanding our own metabolic profiles, and it’s very hard for some of us to get one done. I’ve gone through my GP, my insurance company, and called Liposcience directly with frustrating results.

    1. Can you, or maybe some of your readers recommend labs that does the NMR lipid profile in different parts of the US? (I’m in San Diego).

    2. Are more labs coming on line capable of doing NMR lipid profiles?

    3. Is making the NMR diagnostic more widely available and used a part of your strategy at NUSI?

    ps. Love your Pi day observation, the watch, and your exemplary response to your daughter’s inital encounter with trolls! More posts, please!

    • Hank, sorry to hear you’re having such a hard time. You may need a new GP, though.
      1. I’ll let others address
      2. Yes, Liposcience has licensed the technology to other labs, so should be more ubiquitous in time
      3. Not at all

    • Colleen

      Depending on where you live, you can just go online, pay for the test, and get blood drawn at a local lab. Google NMR blood test and your state.

    • Maryann

      Hank, Helath Diagnostic Lab in VA and Labcorp do NMR.

      Hi Peter, I really enjoyed your q and a format; since you have an interest in hormones I would love to hear you discuss that soon , thank you for all you teach, maryann

      • I don’t recall what I talked about. Did I give my rant on HRT?

    • Jane

      Mayo Laboratories also runs NMR tests.
      I got my results through Pacific Diagnostics Labs (Ventura, Santa Barbara) after asking my new HealthNet HMO doctor for the test.
      Maybe you can check labs around your area to see if they will send out for results from Mayo or other lab licensed by Liposcience. Of course you will need a doctor’s order anywhere.

  • Pingback: Dr. Peter Attia: Newest Blog with Readdressing Dietary Guidelines |



    Watched your video on our Healthcare system. Show this to your Daughter.
    Your Father should be ashamed of himself for being so smart ,articulate, on point
    and rationale about the issues facing ourselves and our country.
    Keep up the good work Brother, we need objective minds like yours out there
    fighting the good fight!

    • Appreciate the kind words, but I’m pretty sure my daughter would rather watch MLP (my little pony for those of you without little girls)!

  • Martin


    Loved the podcast even if it felt weird for you! Would love to here more about B12 supplementation. I feel a strain to get to the daily level of B12 even as a meat eater (not much in chicken or eggs). You stated that you supplement and I was wondering if you could share a bit more on this. Also on k2 and if it’s necessary if you have time! I feel like b12 levels for meat eater and k2 are so uncovered in today’s health news.


  • Julianne

    My LDL went up horribly high (285) on a paleo diet (not very low carb) using coconut cream in my coffee, meat fat and butter – but only in small amounts.
    I was rather freaked but saw some of the posts on high SFA and LDL, started cutting the fat off meat, cut the butter and coconut cream, ate only a little added MUFA to meals. Increased starchy carbs from root veg. Within a few weeks it was down to 150.

    • Looks like you had too much SFA also.

    • calvin

      Julianne, that’s interesting. Noticed exactly the same numbers on me since dropped most of the carbs and replaced them with fats – SFA included. Given the advantages I see and feel from a low-carb eating style, I am not ready to drop it; unfortunately – till now – I did not manage to get an LDL-P count. Maybe because certain diseases are not felt as widespread as in the US, in Europe you are looked by the average doctor as coming from Mars when you ask for certain blood tests. In the meantime, it is maybe a good idea to give a try to the hint of reducing the SFA fraction and then re-measure.

  • Vincent

    Hi Peter,

    Thank you for another great post and podcast. They have been teaching me a lot.
    After reviewing Dr Daysprings lipadaholics case 291(again), i’m left with a couple of questions regarding LDL-P and nutritional ketosis.

    1. Dr Dayspring describes that ketone bodies can enter the cholesterol synthesis pathway and therefore NK can raise LDL-P. Would it then matter if you subsitute SFA for MUFA whilest remaining in ketosis? Or could there be more states of Ketosis? Would it be possible that the consumed ratio of SFA, MUFA and PUFA have an effect on the ratios of ketone bodies with potentially different effects in different people?

    2. I remember you saying to be cautious with genotype testing in relationship with dietary changes. What are your thoughts on APOE genotypes and SFA consumption? Could the E4/E4 genotype be responsible for the subset of people doing poorly on high SFA diets, ketogenic or not?


    Ps. Good luck with your book, I hope you keep it the same style and level as your posts 🙂

    • 1. Don’t know the answer
      2. I’ve seen lots of advice on this topic, but I’m not sure I’m convinced that apoE genotype is the indicator.

    • Deb

      I had the same question about Apo E 4. Peter- why do you not think that there is something important about it? Is there not enough research on it or have you not looked into it?


      • Complicated question and I can’t give a complicated answer right now.

  • Charles

    I think it is important to learn from a young age that no matter what, some people just aren’t going to like you (and that’s ok). Can’t please everyone, I guess!

    “You can be the ripest, juiciest peach in the world, and there’s still going to be somebody who hates peaches.”

  • Chris

    Hi Peter,

    Thank you for all that you do to educate and inform us! Recently, I watched some of your presentation that have been uploaded to youtube. I have one general question. I am not into vitamins that much, but am wondering if there are “staples” to consider to help boost one’s immune system? I am a 46 year old male and usually take d3 and probiotics daily. In your opinion, does this do anything to build immunity? Should I consider a B complex, or a multi?

    I appreciate your feedback.


  • Jason

    Dr. Attia,
    You mentioned ezetimibe in this article… what non-statins (vitamins or supplements) do you prefer to use to address >3500 LDL-P levels? I know you’ve mentioned berberine in other forums. Do you like using chromium to lower insulin resistance? What dose would be effective to moderate high LDL-P levels?

  • Svetlana

    My little pony comment made me laugh. We trip over ponies all day long at the house. Rainbow dash is one of our daughter’s favorites.

    On the pod cast – yes, please continue to do them. I have listened to many of Tim’s episodes and the only ones I don’t like are when they sit outside restaurant in noisy settings or sometimes inside restaurant and too much background noise. I turn them off – too hard to listen. Also agree that it would be better if Tim or some other voice asked the questions. But I would listen either way.

    Thank you for all the info, appreciate your work.

    Best of luck with parenting, some days are hard but the next day can be the most rewarding.


    • I can name virtually EVERY single one of the ponies…AND I can differentiate between the the ponies and their equestria girl counterparts!
      My daughter wanted to name her brother Rainbow Dash (after Michael Jackson) because she thinks RD is faster than Secretariat (my favorite horse–we also have a doll of him).

  • Stathi

    Hi Peter

    “Parenthetically, we also reduced his omega-3 PUFA given very high RBC EPA and DHA levels.”

    Could you please elaborate on this? Can one’s omega 3 levels be too high?


    • When RBC EPA and DHA levels get too high, the blood gets very thin. People with levels over 12-14% are more likely to bleed. Too much = bad = too little.

  • TK

    Suppose hippos (and other species of animals) in the wild are fat – does that make them unhealthy? Any vets on this board?

  • Maryann

    Hi Peter,

    Regarding B12, I have read that people with an mthfr defect can show very high levels of B12 due to years of the non-methylated version not being absorbed. So, for people in this situation, what is the proper test and what level is optimal? Thank you for all you do! maryann

    • Hmmm, I actually haven’t seen that. Not sure.

    • Maryann

      Hi Peter, is a great resource ( have you checked it out yet?). Yes, in the interview you expressed an interest in HRT. ps please let your daughter know that the other girl was probably envious, since your daughter is thin. People will often encounter opposition to their perceived strengths by others who struggle with insecurities. We can respond by having compasssion and saying a prayer for them instead of letting it bother us. Thank you for taking the time to still teach us in the midst of such a demanding schedule. I for one really appreciate it, and I try to share what I have learned with others. Blessings to you and your family 🙂

    • Jane

      Would someone with the MTHFR defect end up with very high homocysteine?

      • Often, yes. The “problem” is differentiating from lack of methylfolte vs. inflammation.

  • ACH85

    Maryann, I’m no doctor, but my understanding is the MTHFR mutation affects folate status (specifically our ability to convert the common folic acid into folate) more than B12. I don’t know my MTHFR status, but I supplement the methylcobalamin form of B12, and folinic acid (not folic acid) for folate, both of which *should* bypass any problems with MTHFR.

    Peter, thanks for the post, and I wanted to add that I too loved the Q&A podcast, and would definitely listen to more. The original podcast with Tim got me to donate what I could for NAFLD to NuSI (I already got a thank-you, no need to repeat) so perhaps if you did more podcasts in conjunction with donation opportunities that would provide a valid reason to have a cohost from NuSI asking you the questions? Also I would be wildly enthusiastic about Q&A’s with you and a member of a research team that needed funding, and I’m sure that would drum up additional targeted donations as well. You could spend some time discussing the proposed research and why it matters, then both riff on related listener questions.

    In case you’re taking question requests for a future podcast…

    Q: You’ve talked about a subset of low carb / keto dieters with crappy LDL and other biomarkers. Do you also see lowered T3 in that subset? Paul Jaminet has talked about a possible cause of high LDL in some paleo dieters being that low glucose causes a reduction in T3 (but not other thyroid hormones) which then lowers LDL receptor expression at the cellular level (this part is Chris Masterjohn’s claim) causing elevated LDL over time.

    This makes a lot of sense to me and jives with my biomarkers, so I’m wondering if that theory holds water in your view or experience. If so, is this a different subset of people than those for whom switching from SFA to MUFA while remaining low carb causes an improvement?

  • jw

    One of the more popular KD authors (and practitioner for a decade or so) does have high LDL-P readings and NMR>3000 but also has been tested and his CCS and CA scans are near zero, so it may not always correlate. (The usual n=1, may not be enough time, etc, etc factors apply….)

    So may inflammation still be at least as important?

    • Jane

      Would you please post the link to “one of the more popular KD authors (and practitioner . . . .”?
      By “practitioner,” do you mean an M.D.?

  • Janet

    I’m in the Bay Area. How do I find a doctor who is willing to perform the basic tests and interpret the results? I want to know what my personal risk factors are and I’m tired of the usual knee-jerk non-science-supported answers. Loved your Q&A on Tim Ferriss.

    • SparrowHawk

      Great question — Bay Area here too and would love to know what Dr.(s) in this region do the same sort of tests and can advise on these variables.

  • Kevin J

    Peter, should I take b12 if I only eat fish? Thanks for the podcast definitely make it a regular thing with tim. But please try to do it together seems like a good time for you both from what I listen to.

  • SparrowHawk

    My cholesterol went from a ho-hum lifetime average of 180 to 575 after adopting a paleo/ketone diet, which I had to do because I had become so severely reactive hypoglycemic I could eat almost no forms of carbs without severe glucose crashes throughout the day.

    So this wasn’t a fashion choice diet. That said, I wish I’d known what you outlined above because I was so flummoxed as to why my cholesterol should be so high when “everyone” was saying cholesterol should normalize under a proper NK approach. Shifting around to fish, duck, other fatty foods maybe got my cholesterol down into the 475 range, but last tested it was still at 510. My cardiologist does not use your types of tests so I can’t compare to NMR.

    Due to food sensitivities I have about 10 foods I can eat. But one of them is coconut oil. Looking at your above responses, you are saying MUFA’s your patient used were olive oil and macademia oil only? Does coconut oil also count in that MUFA category? What other MUFA’s do you recommend for folks in this genetic cholesterol predicament?

    Many thanks — and if you want a truly off the wall addition to any of your studies, just ping me, I’d be glad to participate.

    • Julianne

      When my LDL and total cholesterol went up, I did what Peter suggested and cut saturated fats – coconut oil and cream, butter, and meat fats, especially beef and lamb fat. Instead I use nuts, nut butters, avocado, avocado oil, olive oil and macadamia oil – all sources of mono-unsaturated fats. I increased my carbs a bit as well – more root veg at meals, but because I easily get hypoglycemia I only eat carbs with protein in a meal, and never grain carbs or sugars as they mess with my blood sugar levels. My total went from 380 to 250, all a decrease in LDL.

  • Lauren

    Hello Dr. Attia,
    I’m writing on behalf of Dr. David Katz, founding director of Yale University’s Prevention Research Center, president of the American College of Lifestyle Medicine and founding director of the GLiMMER Initiative. Dr. Katz, in conjunction with Dan Buettner, author of The Blue Zones is launching this global initiative to address today’s alarming trend of chronic disease. This project aggregates some of the most influential voices in healthcare and related fields, rallying around the fundamental evidence-based principles of sustainable healthy living.

    Dr. Katz would like to contact you about becoming part of this lifesaving work. We’d be grateful if you could contact me (laurenakrohn (at) gmail) with an e-mail address where we may send you an invitation and more information.

    Thank you in advance- I look forward to your reply.
    Lauren Krohn, Nutrition Consultant
    GLiMMER Initiative

  • Amy

    Thanks for doing the podcast with Tim Ferris, which is how I found you. Do you have any thoughts on whether one of the signs of a person (a female) who does poorly with SFAs would be acne? Also, I’d like to second an interest in hearing you discuss HRT more in a future podcast. Under what conditions and how would you recommend supplementing testosterone for women? Is estrogen dominance really a thing; how could you know if you have it; what would you do about it if you did? Etc.

    Also, on the podcast you mentioned the various hormonal axes, but do they interact? For example, if you had Hashimoto’s, could it cause your other hormones to get out of whack? Or vice-versa?

    Congratulations on having your second! I’m in the “one and done” camp myself, mostly due to age. Very thankful to get to be a parent, though and, like you said, help my daughter avoid or better deal with the challenges I have faced in my life.

  • Maximilian

    Dear Dr. Attia,
    thank you very much for the podcast.
    Which Berberine Supplement do you take?
    In general, how do you know, that the Supplement actually contains, what it claims to contain?
    Best regards,

  • Mike

    Listened to your podcast with Tim where you mentioned taking Berberine. Are you not concerned with the finding of some studies to its toxicity and effect on mitochondria like this one?

    • Isn’t this an vitro study? Not sure how or why this this would apply to taking 500 to 1000 mg of berberine per day. Not saying it can’t, but nothing I see in this study worries me.

  • Jason

    In response to your Tim Ferriss monologue… what are your thoughts on Vitamin K2 supplementation?

    • Probably good if you believe coronary calcification is bad thing. But that’s a whole other story.

  • Kevin Brennan

    Hi Peter,

    I am Ferriss-o-phile, and came to follow you following the Christmas interview and recent Q&A. Really enjoyed this and would value more of these within your blog! You couldn’t tell it was just you and the mic, after the first few minutes…nice!


    • Thanks, I may work up the nerve to try that again.

  • kara

    I always enjoy reading your blogs. 🙂 I do however have a question about an area of cholesterol that I can’t find much information about. I have read all this information about how high cholesterol is totally misinterpreted, but what about those who sit at the opposite end of the spectrum. The ones of us who have been “high fived” for years over our naturally *good* lipid profile. I was once told by a doctor that I had hit the genetic jackpot with low LDL and high HDL levels. Now I’m wondering if this maybe isn’t such a good thing. =/ should someone be concerned if their cholesterol LDL is too low? (And I’m talking naturally occurring – not statin-induced). And what should they do about it if it’s something to be concerned about?

    • Unlikely, and especially not from a CHD standpoint. VERY low cholesterol probably impedes immune function.

  • Marina

    Thanks for your new post:) I still remember telling a girl she was ugly simply because she was wearing blue (I thought it was only ugly girls who wore blue – pretty girls like me wore pink!) 🙁 I was very young but I made the poor girl cry. I hope her dad was wise enough to give her the same response as you did for your daughter:) The Pi thing is pretty cool:P that moment/ event won’t ever happen again!!! anyway, I loved your post. What a way to procrastinate on my assignment:) thanks always for sharing your knowledge (and other interesting little stories)!

    • I’m just glad life is an integral more often than a derivative (i.e., we’re judged more often by the sum of our behaviors than for a behavior at a point in time–lots of exceptions, of course).

  • newbie

    Thanks for clarifying the name – Ferriss – informative monologue. Your answers are well thought out and clearly presented – thanks for your efforts to continue to educate your listeners/readers.
    So, if I understand your current state, you are in a combo of alternating states of regular low carb metabolism as well as starvation (calorie restricted) ketosis and nutritional ketosis. Did I get that right? Do you feel that these 2 ways to enter ketosis are different entities metabolically, and have different physiologic outcomes/consequences?

  • Robert Channing

    Please give us the interesting thoughts on Vitamin K2! You’ve got me on the edge of my seat for this!

    • Probably not necessary if diet is sufficient. Also depends if you buy the calcification story.

    • Maryann

      Hi Peter, this isn’t the first time that you have said this…what do you “not buy” about coronary calcification ? Thank you, maryann

  • Tim

    What Omega 3 form do you reccomend? Fish, Krill, cod oil etc.?

  • SV

    Great reply. Funny. The fish …Girl subject will always be hard I think. Our girl is so complicated. I do think we can teach a lesson. Tell your daughter to be great at dance no matter if she is Pinkiey Pie or Rainbow Dash they are all great.

  • newbie

    In your podcast with Tim, you said “be careful to distinguish between hypocaloric and eucaloric/hypercaloric ketogenic diets …..they don’t have that much in common aside from their name…..physiologically….” Two questions..
    1) I understand that explaining the physiologic differences may be more than you can do in this comments section, but can you give some links to articles that may help me to grasp the difference? Or some intro thoughts to explore further on our own? I have a particular interest because IF, which I love to follow – caused a spectacular rise in LDL(I am female) – and I am trying to understand the mechanism.
    2) if one is in hypocaloric ketosis, by definition, would it not be correct that there must be weight loss? Or is there not weight loss if it is just intermittently hypocaloric?

    • Definitely not an answer for comment section!

    • webgrrrl

      “if one is in hypocaloric ketosis, by definition, would it not be correct that there must be weight loss? Or is there not weight loss if it is just intermittently hypocaloric?”

      Well, since Peter won’t answer, i will. This part is at least easy.

      No and May Not Matter. 😀

      And the reason is very simple: as you under-eat, your body begins to conserve energy. It is not a 1-speed machine to be easily tricked. It will actively and quickly begin to slow your metabolism and become as efficient as possible to save calories. Because your body doesn’t know you’re “dieting,” it thinks it’s in danger of beginning to starve.

      You may cut your calories by X, but your body can cut your metabolism by X+more. It will drop your hair and not regrow it, stop your period, cease normal fidgeting, cut back on collagen repair, make watching another hour of TV seem REALLY INVITING – whatever it takes to save energy. And after you’ve lost some weight, it will keep itself at the lower metabolic level just to make sure such trauma doesn’t happen in the future! So all you’ve done is slowed your own metabolism.

      You could actually GAIN FAT (and many women do, as you know. We’ve all heard our yo-yo dieting friends complain about this). So don’t under-eat, k? 😀 Your body has evolved to defend its set-point, and does so aggressively. Don’t threaten it; coddle it. When it feels “safe” and you give it the right kind of food and a bit of exercise, it will normalize itself. But its normal is not likely Vogue’s bikini shoot. 😉

      Please see: ?

      Rosenbaum M, Hirsch J, Gallagher DA, Leibel RL. Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight. Am J Clin Nutr. 2008;88(4):906–912. Available at:

      Weigle DS, Sande KJ, Iverius PH, Monsen ER, Brunzell JD. Weight loss leads to a marked decrease in nonresting energy expenditure in ambulatory human subjects. Metab Clin Exp. 1988;37(10):930–936.

      Levine JA, Schleusner SJ, Jensen MD. Energy expenditure of nonexercise activity. Am J Clin Nutr. 2000;72(6):1451–1454. Available at:

  • jacob myers

    your podcast with Tim was great thanks! please do more!

    i wanted to know what you thought about the tsh blood test, bec mine was over 3 the past 3 times i checked in the past 3 mounts and i know you say it should be under 2.5 and i had a lot of hypothyroid symtoms even though my free t4 was normal, and my docter kept on telling me that i have no problem. but then i cheeted for the first time in 6 mounts and a few days later i felt great and back to normal. do have any thoughts about what the cause or problem could have been so i can prevent it in the future?(what tests can i do to check – if it was conversion to t3 or a problem with my gut)

  • Indy M.

    My labwork A1c does not match my at home blood sugar measurements. The following from
    (Ruhl, Jenny (2012-07-15). Blood Sugar 101: What They Don’t Tell You About Diabetes (Kindle Locations 885-890). Technion Books. Kindle Edition. )

    Post Meal Blood Sugars Are a Better Guide than A1c. People who measure their blood sugar at home frequently ask why their A1cs are higher than they expect based on their testing and worry that, even though they are keeping their post-meal readings in the normal range, their risk of complications is still high. There are several explanations for why the A1c doesn’t match post-meal tests. One is that because the formulas used to estimate average blood sugars from A1c readings were derived from a population whose average A1c was well above 7%, it is possible that these formulas break down when applied to people whose blood sugars are near normal. The A1c only measures how much glucose has become bonded to red blood cells and assumes that red blood cells live only three months. But some research suggests that red blood cells live longer when blood sugars are normal, and, of course, the longer a red blood cell lives, the more glucose it will accumulate—even in the presence of normal blood sugars. By the same token, if you
    are anemic or have certain inherited blood conditions that affect red blood cells your A1c may be low when your blood sugar has been spiking high after meals. Other genetic factors may also be involved. Studies have shown that some people’s A1cs are consistently higher than their blood testing would suggest while others’ are always lower—and that these differences persist from test to test.
    So if your A1c predicts an average blood sugar that does not correlate to your blood sugars as measured after many meals, trust the post-meal measurements.  It is most likely that they, not A1c, predict complications.

    So it may be best to make sure, as I did for past couple of weeks(every 6 mos), that my Post Meal Blood Sugars are in safe territory. Somebody mentioned A1c, thought I would add this caveat.

  • Hakim

    Think both podcasts were great. I believe you are a great speaker with a lot of info to offer that it doesn’t matter the setting, it will always be good.

    I’m sorry about the experience you had with your back. Just would like to ask if you can offer your experience in how you overcame your addiction. Maybe a show with Tim Ferriss about addiction as it is a prevalent issue in society not only with drugs but with food sex et cetera.

    • Actually, I would really be happy to talk about that some time. Sometimes I’m so happy to talk about anything other than the “usual.”
      Next time Tim posts Q’s for part III, please make sure to post this and I’ll address it.

  • jacob myers

    I wanted to ask you what type of questions or comments can i post on this blog (not so clear to me)?

  • Sara

    I just want to make the point that I’m a woman and I celebrated pi to 10 significant digits and dragged my fiancé into the celebration too. Alas, as an engineer, I probably don’t count as a woman.

    Thank for your amazing series on cholesterol and ketosis here. Thanks to your information as my massive starting base, my HbA1c is now 4.9% and my trigs are at 61 (even with APOE ?4!)

    I do have something to say about the state of the health care system in Switzerland while you opened the debate. We have increasing costs here, but as in Germany, private insurers cannot make a profit from basic services (and basic services are quite extensive.) As a Canadian student, affording physio therapy was a struggle with my student insurance back home; here, almost everything is covered with almost no wait, at a relatively high monthly cost of ~400CHF(or €)/month with a deductible of 300 per year. It’s a bit of an oddity to me that I can get a non-urgent MRI in 2-3 days, or see a specialist on the same day when I could easily wait a week. Do the doctors have a dearth of patients? Surplus of doctors? I can’t imagine this being sustainable since every paranoid patient can easily rack up their bill with unnecessary diagnostics. Maybe the Canadian cap is a reasonable measure in certain models, since a specialist in Switzerland can dispense any drug such as Remicade or Avastin at a 15% markup for any patient calling for it…. Given the cost of these drugs, this is a higher profit than I would expect for a practicing physician to make just by asking a nurse to dispense a drug.

  • Jane


    By the way, I also loved your initial response to your daughter — laughing out loud!!!
    Performance is certainly a good reason, and it clearly derives from overall health, I kind of wish you had said, explicitly, that your health was the reason you avoid sugar.

    You said above, in response to Maryann, that you would discuss coronary calcification on a podcast. In that context, vitamin K2 seems like a key issue, and one of great importance to those of us who are now seniors. I would really like to know what you have to say!!!!! And, by the way, although writing a response might take more of your time, it is certainly a more efficient way of learning for your audience.

    Although you do link to a podcast in this posting, I did not even know you were publishing your ideas in the aural format.
    Since your eatingacademy is one of the best sources of information online about diet and health, and science!, I would like it if you would find a way to list the links to the podcasts here.

    FWIW, I signed up for emails from NUSI, but have yet to receive a single one. Even links from them about the designs of their experiments would be interesting to me.

    Thanks for all your hard work,

    • One of the blog readers is offering to help me post the transcripts of the podcasts. Hope to get to that in the next month or so, also.

  • Jeff

    Dr Attia, what levers would you pull if someone has a slightly elevated lipoprotein a? I enjoyed the podcasts, and am interested in hearing what protocols are to be taken. Thank you for your writing.

  • KMK

    Hi Peter,

    Regarding your darling daughter, may I suggest that now would be a good time to help her learn about body-types, and the importance of appreciating and working within her/one’s own?

    Is she into the show Dance Moms? It features (in addition to the Moms and star dance instructor) a pre-teen dance competition team. All the girls on the ALDC team are trim, beautifully athletic dancers. Even at this age, differences in build are apparent: longer limbs/neck on one, a heavier bone structure on another, etc.

    Introduce into the mix (as happened on a recent episode) a very small-boned, long-limbed, remarkably lithe new girl and the others might well look rather like manatees! ONLY in comparison.

    It is so very important for a developing girl to appreciate her uniqueness and cultivate her individuality!

    Regards, KM

  • CM

    I just listened to your ‘monologue’ on my morning commute. GREAT JOB! I had to go to Tim’s show notes to find your info. My doc & I have great conversations on most of the topics you covered and will no doubt enjoy the podcast as well.

    Please continue those recordings as your time allows.

    I also implement a ‘productivity’ system similar to yours. Being very visual, the color coded 3×5 cards were a natural fit. Since you’ve mentioned the popular GTD book it prompted me to check it out and see if I can improve/refine my system based on someone’s effort to actually write a whole book on the process!

    To the issue of children; I have 5yr old Triplets – my cross to bear. Hence my re-surging interest in uber-health/performance/patience/parenting etcetera

    Cheers from sunny & warm Tampa, Florida!

  • Aleut

    I listed to both podcasts you made on Tim’s show several times. Thank you for taking the time to make them.There is a wealth of information that comes in a constructive and very clear manner. Either format was good and made for easy note-taking. It would be great to expand on the topic of female hormone replacement in the next episodes and if possible, how to attain an optimal hormonal level rather than being in the ok zone. (eg. Thyroid level on the really low side of the ranges considered normal.)

    I also second Hakim’s post: a podcast on addiction (eg. food, drugs, exercise, etc) would be fantastic.

    Thank you.

    • That assumes I know something (anything?) about addiction. I would hardly assume I’m worthy of offering valuable insight on that topic.

  • Jeff

    Follow up on the last comment. My doctor said he’d like me to radically change my diet instead of taking medication, so that’s great news. However, I’m not sure how much diet will change my LP(a) number if you say that diet or drugs don’t make a difference. He had medical literature to say otherwise. I’m glad he’s willing to retest me in 8 – 12 weeks to see if my number has gone down.

    • Lp(a)-P is virtually unchanged with diet or drugs. The goal of treatment is to reduce non-Lp(a) LDL particles as much as possible. The real issue, however, is that we don’t have great insight into the functionality of Lp(a) particles (i.e., are some more atherogenic than others?).

  • Claudio

    Peter- I loved the podcast you did for Tim. Any podcast by you in any format is something I’d find interesting. Sounds like all the positive feeback will result in more of those (regardless of format).

    The part of the podcast about ketogenic diets not being suitable for a large percentage of people really sparked my curiousity (spelled the Canadian way!). Is it possible that these people:

    – Didn’t follow a well formulated ketogenic diet?

    – May have dropped their carbs too fast which can create a stress response. If carbs are dropped too quickly and the person is insulin resistant or metabolically damaged, the body will not know hot to make and use ketones, and hence the inflammatory response?

    – May be secretly or unknowingly over-eating carbs while attempting a KD, which doesn’t mean that they are not suited for a ketogenic diet. They just weren’t following a proper ketogenic protocol?

    Peter- I totally understand why you came out of ketosis though. It sounds like you travel a lot. 2-3 days per week in airports and hotels while trying to maintain ketosis would be a hard grind.

    • All of the above are possible, but I’m referring to a person who is biochemically in ketosis, and even feels well, but experiences a deterioration in metabolic health.

  • Alyssa

    Just watched your Ted talk. Powerful and amazing. I am not a dr but have been interested in the topic of gut bacteria, specifically the weird story of the woman with c diff who had a fecal transplant and gained weight (transplant donor was obese if I recall). your comment in the talk about the reason for fat storage (a healthy reaction to the glucose bs metabolic syndrome’s reaction) reminded me of the non scientific websites talking about gut health. I will read your blog and site to see if you had any thoughts in this area , but I had to say what an amazing Human being you are. Thank you for inspiring.

    • Yes, that is interesing. But keep in mind, someone with c.diff is suffereing from debilitating (read: deadly volumes of) diarrhea. So it’s quitely she gained 20 pounds in response to not having diarrhea. I’m not saying this to discount the role of gut bacteria, but we need a lot more study to know what the heck is going on.

  • Jennifer

    Though a little off topic, I can’t find much information anywhere and wonder if you might have some advice on the topic. I have gained a lot of weight (60 plus) pounds with my 4th pregnancy. A combination of lack of mobility with pelvic complications and what went on my fork. I lost a substantial amount of weight after my first son 8 years ago on a Keto diet (Dr. Bernstein diet clinic in Canada) and kept it off. I cannot go to the clinic when breastfeeding but the sugar/carb addict that I readily admit I am, cannot lose weight without being on a keto diet and I don’t want to keep this weight on for a year or longer. Is this type of diet acceptable/safe to do while breastfeeding? Thank you so much!

    • Jennifer, I *really* wish I knew the answer, but I don’t. I have noticed a really strange phenomenon in women status post pregnancy #4–the recovery is nothing like the previous 3. Very anecdotal–I’m talking about an N of 6 or 7–but amazingly consistent. My intuition tells me it’s a combination of all four endocrine systems being disrupted. But I haven’t figured out yet how to tweak back.

  • Christine

    I just watched your TED talk and cried. I was diagnosed with IR 5 years ago, having never heard of it before. I’d been overweight and obese my whole life and just told to eat less, move more, stop drinking soda (I don’t like soda). I thought I was losing my mind. I used to cry myself to sleep and pray to just die before I woke up, because what girl wants to be 250 pounds in her 20s? I went on a very restrictive diet (medically supervised) and I lost 75 pounds. I’ve maintained a 60 pound loss for over two years. I’d like to lose more… I’m working on it. My blood tests come back normal now, so I may have beaten the IR with the weight loss… hooray! But I have a very unhealthy emotional relationship with food that I’m working on. It’s a journey but I was in tears watching your talk because someone finally understood me. Thank you.

    • Christine, I can’t imagine (let alone pretend to understand) your pain. I wish my apology–on behalf of a failed research and medical community–would even add a modicum of relief. If it helps, please know this…this is not your fault. I would bet every dollar I’ve ever made and will make that 1000 people could have mirrored your every behavior in life, and very few would be suffering what you are suffering. You just have a much higher susceptibility than everyone. Compounding this, I’m sure most (all?) of the medical advice you’ve received has been junk. But more than anything else, regardless of the state you’re in, you definitely deserve empathy over judgment. Perhaps, if you’re willing to share where you live, a reader may have a suggestion for a doctor worth seeing?

  • Wesley Hurrell

    Im a competitive endurance athlete who has always been skinny (~10% bodyfat) who switched to LCHF for endurance and health benefits (i.e. not to lose weight). After going sub 10h in my first ironman and being on diet for over a year now, I have just started to notice my blood sugar increasing (i.e. >6.0mmol/l fasting). This is really unusual for me and I’m concerned it may reflect that the diet is not best suited, although I have experienced (and enjoy) most of the benefits of keto etc. Can you comment whether raised blood sugar is part of the high LDL-P picture you see with some patients on LCHF?

    • Two gueses–elevated cortisol (not desirable) or physiologic insulin resistance (not a problem).

  • Tom

    I would love to get your view on IBS in the next podcast.

  • JC


    My wife and I do low carb and have for a long time. We feel great and look great. We want to have a baby and we looked online and many doctors were saying that low carb is bad during pregnancy and can cause problems for the developing baby. Is this true? There is a lot of conflicting info out there and we’re not sure who to listen too, but we trust you.


    • No real data on this topic. I would assume ketosis is not ideal for pregnancy, but crap-carb restriction is.

  • David Feig

    How much Methy-folate do you take and do you measure your homocystine levels to adjust your dose?

  • Phil

    I think the issue of the genetic responsiveness the saturated fat might even be more complex that just a division of those who need to limit SFA and those that do not.

    My diet goes back and forth from Ketogenic to Paleo depending on where my weight is. After several months of using coconut oil in my coffee in the morning, and eating several eggs in the morning, and placing no limit on red meats, my labs showed i was in normal range for LDL. But was 20 points above normal in my HDL, prompting my primary care physician to say “Outstanding numbers, keep up the good work”.

    So, I made the mistake of increasing my coconut oil consumption to several times a day.

    It was then that I started to show signs of PVD. My feet and hands were constantly “falling asleep” when put minimal pressure on them.

    As soon as I backed off on the coconut oil (one tablespoon a day), things went back to normal.

    I think even for someone who responds well to saturated fat in their diet, that there may still be a safe threshold to stay below.

  • Kristin

    I just watched your Ted talk and am contacting you because I believe I’m on the road to getting Type 1 diabetes and noticed a pattern of weight loss and I want to do everything I can to stave it off. My father and much of his side of the family are Type 1 diabetics. I have lived in fear my whole life of developing it. My father developed it around age 38. I am 30. I recently have noticed through routine bloodwork that my sugar happens to be running higher than usual. I’m talking a few points above normal. I had the doctor check A1c and that too was one decimal higher than it should be. This concerns me that I am about to develop type 1 diabetes. The other factor which interests me that you spoke about is weight. I have been losing weight constantly for 3 years. I have been trying to gain it back to no avail. I am 5 feet tall and weigh 94 pounds, currently under normal BMI. To try to gain weight, I have been eating more sugar and fat, which is probably a bad idea, but I have no other ideas. I talked to my parents and she mentioned it was strange because my father also “lost a ton of weight” prior to getting diabetes. Could this weight loss mean something? Our thyroids are fine, testosterone/hormones, etc. are normal… but the weight loss is something that interests me. Admittedly, I do have some other autoimmune issues, and my appetite is not what it used to be, but there is no reason for me to be underweight like this and it frightens me that I’m following the path my father did. Can you please offer me any insight on whether this weight loss phenomenon happens to others before being diagnosed with type 1? What can I do to prevent getting it or at least delaying it? If I can be of any help, research wise, please let me know. Thank you.

  • Julia

    I listened to both your Tim Ferris Podcasts. Three times. Each.

    They were great and I felt like I heard something new each time. Or maybe I’m a slow learner. 😉

    Anyway, two thumbs up! Thank you.

    • Yikes! Julia, we gotta work on getting you a better life! I better come up with some new material…

  • William


    I just wanted to ask where you get the clip art for each post. I am making a presentation and was inspired by how good your blog looks.



    • Sometimes I buy, sometimes I make, sometimes I take.

  • Jon

    Enjoyed your podcast episodes. I am trying to find a family practitioner that specializes in personalized treatment for his/her patients.I think the days of blanket treatments are in its final days but I’m see it’s early in the process to find the physicians who have the knowledge and wherewithal to understand one size doesn’t always fit all.

    Are there any organizations that these doctors belong to ? Or is there a way you could point me in the right direction to finding the right type of doctor that understands this type of treatment? Thank you.

    Southeast Florida

    • Not really…there are a lot of marginally helpful terms like “integrative” and “functional” that get thrown around, but unfortunately quality can’t be determined from title, website, or any other quick metric.

  • ido


    I’m following a KD for a couple of months, following a half year of a moderate HFLC. Feels great, etc…

    particle is a particle is a particle. If you don’t know the number, you don’t know the risk! Everything else (hdl, trig, etc..) is secondery.

    I’m not a US resident, so unfurtunately, I have no way making NMR test. But I’m still trying to make a smart decision.

    given that I understand very well your concordancediscordance point (and given my ldl-c:250mgdl which was 110 a year ago), and given I don’t want to “let perfect being the enemy of good”, it’s still, mathematicaly true, that considering all KNOWN details about me, I’m at risk, right?

    I feel like in a kind of a matrix movie. In the past, I had the blue pill: I was happy with my absolute health illusion (hdl: 29mgdl). Nowdays (hdl: 65mgdl BTW) , after I took the red pill, I’m Worried (atherosclerosis is more risky than all types of cancer combined!) Because I have no way knowing my risk.

    Is there any second best for NMR test (VAP is not, right?)?

    1. It’s obvious to me that it’s impossible to give medical advice over the internet, but telling me to consult a physician, after declaring that most of them do not learn all the relevant material… ?

    2. I guess that consuming a lot of Olive oil and macademia nuts, dose not make sence from evolutionary point of view.

    Thanks in advance for any comment.

    • It is possible outside of the U.S. to have apoB measured. This is a good proxy for LDL-P.

  • Irene

    The podcasts are great! Please continue. You left me wanting for more on aging topic.

    What do you think about “Carb Nite Solution” – intermittent simple carbs loading during LCHF dieting?
    Does it really help to reset hormone production where a body’s got adapted to LCHF?
    Is it a good thing or bad thing to practice?

    • I don’t know the answer, unfortunately.

  • Garry

    Peter, have you thought of doing a post on sleep deprivation and weight gain. Chronic sleep deprivation is so prevalent and many people don’t seem to know that it’s contributing to their weight gain through higher cortisol levels, increased hunger and reduced metabolism.

    • Probably worth a podcast…easier for me to do than a post, but yes this is a very important topic.

  • Sam knutsson


    I’m writing to leave some feedback.
    Loved episodes you did on Tim’s podcast.
    Understandably, the format on the second one must’ve been uncomfortable. Doing a monologue requires a quite high opinion of oneself. Nothing wrong with that. People with expertise should share their expertise with others who are interested. The problem is when the ego is unjustified.

    The suggestion I came to leave was that, if you did any regular teaching or discussion on your topics of expertise or things that interest you, perhaps with questions from others or with peers of yours as guests, I would be a regular consumer. I’d love to learn more from you. Even if you’re not sharing expertise – but questions you have; questions you’ve been able to form based on your expertise, it’d be very interesting.

    Just as writing helps people think (for many, writing is synonymous with thinking), teaching can do the same.

    Quick question:
    For a normal person without disease, would it be more useful – a better guideline – to focus on one’s amount of triglycerides or fatty acids (serum, tissue; i.e. body-fat level, and hepatic) rather than cholesterol?

    Or, formulated differently:
    Is it okay for a person to eat 4-6 eggs a day (1g+ intake of dietary cholesterol), if it helps him maintain low hepatic and body-fat (8-10%) levels?
    Is tissue fatty acids a better metric for me to use than serum cholesterol?

    • Sam knutsson

      Is it okay for a person to eat 4-6 eggs a day (1g+ intake of dietary cholesterol), if it helps him maintain low hepatic fat and body-fat (8-10%) levels?
      *Corrected the question. Sorry.

  • Mike

    can you discuss anabolic steroids. Specifically, if there are ‘moderately’ safe steroids on short term to increase muscle mass long term. I have no experience or research into this topic, but have a feeling what we hear in the media and gov. might be stand up to science. Off base?

    • Well outside the scope I what I discuss on this blog. You are correct, though, the media and gov’t are as accurate on this topic as they are on nutrition.

  • Stephen

    I love Quest Bars, but at $3 a bar, they’re a pretty expensive snack.
    Some people have been reacting to this by making their own Quest bars using VitaFiber Syrup (ISO Syrup) and Protein Powder.
    Is anyone familiar with VitaFiber Syrup (ISO Syrup), and its role in role in a healthy, low carb diet?

    • Stephen

      I took the plunge and bought a 1.24KG bottle of VitaFiber. I got it wrong in my previous post; it’s called IMO Syrup- not ISO Syrup.
      They describe it as, “a sugar-free, low calories soluble dietary-fiber and prebiotic with a mild sweet pleasant taste.
      It is a high quality mixture of short-chain carbohydrates called IMO (Isomalto-oligosaccharides), which is enzymatically produced from starch source.
      Total Carbohydrates 4g
      Dietary Fiber 3.5g
      To make a Quest-type bar, I heat up 3 Tbsp of IMO syrup, mix it up with 25g of 100% Whey Protein powder (vanilla), mix it together, refrigerate it for 30 minutes, and voila- a home made Quest bar!
      You can add walnuts, almonds or whatever during the mixing phase.
      Any comments on the health value of a delicious snack like this?

  • Myddryn

    Do you have any quick tips about chronic bloating? It’s a really common symptom for a lot of people but there is so much information out there. How do you make sense of it? I seem to not get bloated in ketosis. But I don’t know if that’s carbs, fructose, lactose, gluten, or something else. Any suggestions?

  • ido

    Petet, you wrote:

    “As a doctor I can’t look a patient in the eye and tell them a sky-high LDL-P is ok because they don’t eat carbohydrates.”

    you KNOW science proved that high LDL-P is bad (for carbivours). you told your patient to exchange SFA with MUFA. the result: LDL-P fell dramatically. As a DOCTOR you succeed, you fixed hisher NUMBERS, no argue about that. as a DOCTOR you can look stright into his eye, because you did a pefect work. probably better than other doctors, that would advice to exchage with PUFA (because it reduces LDL-C, (while… increasing atherosclerosis and mortality , oops…) )

    Peter, if you will to answer my question, please be aware, that I’m aware that my question is a SPECULATION. obviously it’s a malpractice to make speculations with a patient. no need to explain or emphesize that point to me.

    saying that, here is my question:

    as Peter Attia, who is not just a doctor, but he also always had a tendency to want to anthropomorphize every thing, looking at the whole biologicalevolutionalenthropoligical picture, and (I think, correct me if necessary) you generally believe, the amazing animal-body-machine, under normal conditions (which isn’t carbivourity, as human concerned) probably won’t do something that would heart itself (like producing too much of dengerouse LDL-P endogenously). can you really look stright into this patient’s eye and tell himher that you BELIEVE (just believe, because you don’t realy know) he did something biologically&evolutionary logical, and therefore his health is probably better now?

    sorry this comment is becomming too long… but do you see what happens? treatments LED BY MEASUREMENTS. if you can’t measure something, it dose not exist! as long as it was imopossible to measure LDL-P, it was LDL-C-regime. people were told to reduce cholesterol intake, while there was no proof that it’s even influence the MEASUREMENT: LDL-C…

    nowdays, we do not know to measure HDL-P-functionality (and that is something real!, although we can not measure it, and therefore it dose not exist, while evaluating treatment), or maybe (i have no clue) we do not know to measure the “endothelial-wall-cells-resistence-to-illegal-ldl-p” (I have just invented that, of course). the treatment aim to fix the numbers of our current best measurement, which is, as for 2015, is LDL-P number, under the HOPE that this is the health-proxy.

    I’ll appreciate any comment. sorry again for the so long story.


  • Joanie


    Love all your info, your fairness and openminded-ness!

    RE: Talk 1…are you aware that Dr Steven Gundry has been talking about the subgroup of the population that does not tolerate animal fat (as measured by their biomarkers)? He states that it is the ApoE 3/4 or 4/4 gene that is the culprit and that these individuals should stay away from saturated animal fat. I believe this about 20% of the population.

    • I’m familiar with argument. Not sure if it’s apoE mediating the effect or something else (e.g., apoCIII).

  • Matthew

    Loved the Podcast with Tim Ferris; this is how I found your site. Appreciate all the effort put forth at better understanding the physiology behind our optimum nutritional needs! Look forward to more to come. I thought the format of your “self format” answering questions turned out great!

    Best Regards
    Matthew Peterson, MD

  • julie


    I have been following VLCKD and am having some difficulties with my blood glucose levels. It appears that I have to keep my carbs down to less than 20g per day to maintain blood glucose levels between 80 and 100. Whenever I take supplements such as vitamins, always seems to go up 20 points. Any experience with this? I am very slender 5’2″ and weigh 95 lbs and wanted to follow KD to be healthier. I’m obviously not trying to lose weight and try to make sure that I take in enough calories via fats to keep my weight stable. When I try to add more carbs(vegetables) my blood glucose levels go up even further. I have never had an issue with blood glucose before and am curious how I can find out if I have become physiologically insulin resistant and if so, how to reverse that safely. In addition, my overall cholesterol and LDL have jumped to 379 and 280 respectively, way out of range!!! Could this diet be a factor in this?

    • Sounds like physiologic insulin resistance.

  • Cindy

    Dr. Attia,
    I have a question regarding calories in Keto centric diet. One of your article mentioned that calories does matter (too much calories), but can too low of calories affect weight/fat loss in keto?

    I’m 35 yr old female, 5’1″, with 40 BMI, and I try to net 20-25g of carb. My Macro Nutrient is 10% carb, 25% protein, and 65% fat.
    I’m having issues losing when I net 1000 calories a day (I would eat around 1300 and workout for 33 minutes on elliptical). Is there an minimum calorie for keto centric diet? Should I eat the calories burned (exercise)?

  • Aubrey

    Dr. Attia,

    I work for HDL Inc, and many of my coworkers and I have started following you because our lab tests showed we were insulin resistant. I am 22 and have a BMI of 24 ( I supposed I fall into the 6 million who are of healthy weight but insulin resistant). I have been on a “ketogenic” diet for about a month and have gained .6% body fat. I was consuming a large amount of dairy and I would presume that is what caused the weight gain (my carbs have stayed under 25g for most days). I was curious if there is a way to prove (through lab testing) if my body/ insulin does not tolerate dairy? Because I work at HDL I have access to the lab testing. Do you have any other suggestions that I should try for adjusting my diet? Even if they are just general things to try- it would be greatly appreciated as I am getting a little discouraged!


    • Not that I know of, and even if there was a way, I wouldn’t trust it. The gold standard is elimination. Knock it completely out for a month and see what happens.

  • Eric

    Hi Dr. Attia,

    Just listened to your stuff with Tim Ferriss – very interesting as always. Had a couple questions:

    1. Maybe you already answered this somewhere but you were trying different protocols to enhance the type of exercise you seem to love which is endurance sports. You did “Super Slow” for awhile and then later did some sprint training with the fellow in Carlsbad who trains footballers for the combine. I’m curious what the result was. Based on my experience, the white hot intensity of super slow would make you feel stronger on the bike more than the sprint training.

    2. Volke and Phinney have spent their careers trying to prove that ketosis is a safe metabolic “island” on which to reside. The data with some of your patients seems to say otherwise. In other words, even in deep ketosis, one cannot eat unlimited amounts of saturated fat. (And I’m not say Phinney said that) I’m in ketotsis – I fear that if I start to introduce carbs back in, the fat-burning ability goes down and you venture off of the island into maybe unsafe waters. How do you do that – I suspect the only way to know is to get blood tests.


    PS Is your daughter any good at drums? I’m sure there have been some great female drummers but when the topic of greatest ever comes up, everybody throws out names like Neal Perth, Travis Barker, Dave Grohl – it’s time for someone to throw a female name into the mix!

    • She is good at drums, at least according to her teacher who says she can do stuff most 11-year-olds can’t (she’s 7). Speaking of great drummers, Neil Peart, and prodigies, this kid is from another planet. I can watch/listen all day:
      Now that I understand drumming somewhat I am especially blown away by how this boy plays. Peart is one of toughest drummers to mimic.
      But more than anything I’m blown away by the sheer pleasure exuding from him!

  • kelly

    Thanks for this post… good stuff.
    “there are some people who do not appear able to safely consume massive amounts of SFA.”

    As you point out, context matters.
    No arguing that consumption of massive amounts of SFA in a high carb context doesn’t end well for most who try it..
    But what’s it mean in the context of a VLCMPHF? As you say, “Time will tell”..

    I’ve consumed most of what Dr. Dayspring has out there. Awesome resource and I’m thankful for his dedication to educating anyone with a curiousity and an internet connection on this complex topic. He makes no bones about being big believer in statins to treat high ldl-C and ldl-P… The case he makes for “discordance” (normal ldl-C yet high ldl-P only revealed through NMR test) opens up a very large patient population to the possibility of statin therapy that would otherwise have been missed… That’s great if you think statins (which do affect the numbers) saves lives. I’m not convinced that they are that effective at saving lives.. I’m not a Doc, just a dude obsessed with learning whatever I can on the subject..

    Yeah, he admits once in a while that people can be discordant the other way (high ldl-C and low ldl-P) allowing folks who would otherwise have been recommended a statin based on high ldl-c to “safely” turn down the Rx, but those are few and far between..

    He’s honest enough to admit that we just aren’t sure yet IF these values even matter in the context of VLCMPHF lifestyles.. “but do you wanna take that chance?” seems to be his question..

    I get a sense that he’s a guy with a hammer looking for nails- Maybe that’s unfair.. I’m admit I’m biased the other way, against pharma intervention, so maybe the truth is somewhere in between..

    I’m one who’s ldl-C and ldl-P shot up even as every other risk factor flew in the “right” direction.. VLCMPHF (usually keto). How do I answer the “do you wanna take that chance?” question that Dayspring is right to ask… As you point out, Context matters..
    1. understand the downside of statin therapy
    2. understand the upside of statin therapy
    3. what other interventions could impact these numbers, assuming I believe they represent increased risk in my context..
    4. what other pieces of info can I gather to put these numbers in greater context?
    -CIMT- age appropriate/no detectable plaque
    -Calcium Heart Scan – score of zero
    -Inflammatory markers – very low
    -current state of health/body comp – awesome

    In my context, I’m not losing too much sleep over the high P count.. But I think cutting SFA a bit to bring it down can’t hurt.. So That’s what I’ll do.
    If I was 40 lbs overweight and had a heart-attack in the rear view mirror maybe I’d answer this diffrently and take the drug..

    Anyway, sure appreciate the education you’ve given me over the years.

    • A very thoughtful approach, Kelly. I can’t argue your logic. To your question, I’m giving a talk at UCSD on June 3 (anyone reading this who cares to attend, save the date…I’ll figure out where and when) about exactly this problem. What tests can we do on someone to determine the presence of vulnerable plaque? How can we more effectively measure oxidized LDL particles and sterols?

    • Maryann

      Hi Kelly, I enjoyed reading your post. I believe ldl-P is the number of significance for risk; however, additional advanced testing would put it in context. For instance, if someone also has high Lp(a), which is a big risk factor, this is genetic. Since it can’t be modified by lifestyle or medication, the other risk factors would need to be addressed instead.

  • John

    During recent podcast with Tim Ferriss you mentioned using Berberine as supplement. Are you not concerned with following findings that may render it harmful?

    “Several mainstream studies claims to have found that berberine inhibits DPP-4 and raises the concentration of the incretin hormone GLP-1.”

    “Mainstream research also finds that berberine has a significant impact on your liver. Repeated use downregulates several important enzymes (P450 cytochromes ) that the body uses to eliminate drugs.”


    • Actually, berberine activates APMK as a known mechanism. If it also inhibits DPP-4 and acts as a GLP-1 agonist I would be pleasantly surprised. These are pretty good mechanisms for someone who is IR. The other thing berberine does is inhibit PCSK9 in those who tend to overexpress. Maybe a good topic for me to address in another podcast.

  • Hans

    Dr. Attia,

    Really enjoyed the tferriss podcasts. You should definitely do more in that format.

  • Vance


    I will try to be general and not post my NMR numbers in hopes that you will comment in response to my question that follows ????

    I’ve been LCHF for a year and in ketosis since the first of the year. I’m a pretty lean 42 yr old white male with no markers for metabolic syndrome and my LP-IR was <25. Pretty much all my biomarkers are good (at least as far as I understand) … to include HDL, TAG, FG and h's-CRP… except LDL-P which is high and about 50% of that is small LDL-P 🙁

    So… in response to this post I have already started reducing SFA and my doc and I plan to do some micro nutrient testing to see if I'm deficient in something that may be impeding my liver from clearing LDL-P.

    My question is this and it's in reference to LP-PLA2 and Part VIII of your cholesterol series…

    Do you think an LP-PLA2 test is needed or would be helpful with an hs-CRP (cardiac) of 0.79? I guess what I'm asking is can LP-PLA2 be high when CRP is low?… or would CRP also always be high if LP-PLA2 is elevated? (although CRP wouldn't necessarily indicate "angry arteries " given it's broader scope)


    • LpPLA2 is still in its infancy, IMO. I use it routinely, along with MPO, hsCRP, homocysteine, and fibrinogen, as a proxy for inflammation. However, we’re still not entirely sure how to interpret discordant info. So yes, the situation you describe is something I see from time to time.

  • Charles

    Hi Peter

    Loved the appearances you made on the podcast.

    I completely reversed my non-alcoholic fatty liver disease after adding Choline supplementation (500-1000 mg/day).
    Despite meat consumption (250-400g daily, on average)!

    Thought you’d find that interesting, since it’s your area of research.

    Good luck on NuSI! Hope you do more audio appearances. 🙂

  • Alexey

    Hello Peter,

    My name is Alexey and I want to thank you for such detailed information that you’re sharing on your website. I’ve heard about it from my friend. At this moment he’s very happy with the diet, losing weight very fast and become much more fit during last year. Especially last several month after starting Ketogenic Diet. I’m happy with the Zone diet, but in general it’s something like 30/30/40 plant I’m pretty sure you know what is this, so I’m not going jump in details of that. But I’ve a question please, his goal is to lose weight and after what I’ve read Ketogenic Diet is perfect for that, but I can’t find information if I’ve an opposite goal – Gain Weight, more muscles. Can I still use Ketogenic Diet for my goals and if yes how it’s going to work for my gain weight, I understand how it’s working for people who want to burn more body fat, but how it’s working for people who want to gain more muscles? Thank you very much again I’ll really wait for your answer if you’ll have time to answer.

    P.S: My sport activity is CrossFit.


  • Ash

    Enjoyed the podcast, good radio voice, didn’t sound awkward at all. You are fantastically articulate and do a great job of making all this understandable.
    One question:
    Have you considered the possibility that LDL-P could just be the big feet? (to reference your age-feet-reading comprehension) i.e. not that cause but just correlating?
    E.g. LDL could be created / recruited as past of an inflammatory response?

    • Possible, but lots–and I mean lots–of data to suggest it’s not big feet.

  • Indy M.

    “…n one particularly interesting case, a patient in self-prescribed nutritional ketosis presented to me with an LDL-P of more than 3500 nmol/L…”

    Dr. Attia –
    do you recall the small LDL-P value, ballpark, by any chance?

    I personally have had instances where
    LDL-P is ~1200 but small LDL-P is ~ 100(8%) ;
    LDL-P ~= 1700, but small LDL-P ~= 570(34%).

    Comments on significance of the relative value of the small LDL-P wrt the total?
    Thanks in advance!

    Indy M.

  • Judithann Ortiz

    Good afternoon, is there a reason why some people crave carbs a month after being in ketosis, but not yet Keto-Adapted?

  • Justin

    Peter, thanks for the blog and the great videos. I am an MD who lost 40 pounds on low-carb over 3.5 years ago. I have coached a lot of people using the low carb, high fat methodology to improve weight, diabetes, blood pressure, etc…

    In my own situation, HDL has remained high 76-77 for 2 years, and TG remained low 42 to 48. But, as you mention in this post, my LDL-P (and calc LDL well correlated) has increased for the last 2 years to numbers I am not quite comfortable with (as you mention in this blog).

    With a family history of heart disease (father sudden cardiac death at 42), and me age 37, I would like your suggestion for an expert to consult with regarding these cholesterol numbers. I have considered just making an appointment with William Davis or Eric Westman. However, you seem to have the firmest grasp on this subject from my reading, and as such who would you recommend that one visit?

    Of course, this (meaning me) would be a fabulous case for Robert Atkins himself, with his years of experience to draw from. But he is no longer with us.

    Justin Anderson, MD

    • Justin, Tom Daypring is my mentor and arguably the most knowledgable lipidologist with respect to the issue you raise.

    • Bob Niland

      re: … considered just making an appointment with William Davis …

      Just to calibrate any expectation here, my understanding is that Dr. Davis has wound down his conventional practice. He may or may not be accepting individual consultations.

      That said, his cureality dot com site (an evolution of his older trackyourplaque site) has an active forum that appears to have an over-representation of users with ApoE polymorphisms, and dietary/lifestyle approaches for that is are frequent topic, with participation by Dr. D.

      This is subscriber content, so I don’t feel at liberty to copy&paste. I can say that the current recommendations do NOT include statins, in case anyone was wondering.

  • Andre

    Peter, I am a long term reader follower, and for a 3 years now into high fat, now settled on moderate version that permits some whole grain rice and tubers, but not wheat/GMO soy (mostly to prevent glyphosate) and basically mostly organic with ample leafy greens and fermented stuff and as much moderate excercise as I can afford.

    I had also been into lab testing a lot, but stopped it due to the dificulty of really – even after reading EVERYTHING – interpreting the results (basically after measuring APO-A,B and then CRP, IL-6 etc I figured out that probably the only thing with predictive power is blood sugar and triglycerides in my situation, ox-LDL is not available here).

    So, basically within the last 1-2 years, have there not been any significant discoveries what markers to use? (I am APO e3/e4, so my LDL tends to be higher as the e4 is not that efficient AFAIK)

    • I feel your pain…and just lectured on it at UCSD last week. The missing link it a completely sensitive AND specific marker of endothelial inflammation. Good news is there are some exciting technologies on the way.

  • Ben

    Dr Attia
    Enjoyed your blog and your podcasts with Tim. I guess I am a little behind in my reading. I am one of those who went bulletproof, and felt really good, until I got my first blood work back. Cholesterol went up from 250 to 350, tsh went up and my CRP went from 0.5 to over 5. Trying to allow for an adjustment I gave it some time. My LPa was over 3500. The numbers only got slightly better over the next year but having drunk the koolaid I stuck with it. I felt really good. During that time my CRP was random, bouning between 5. I my apoe is type 2. I ultimately read everything I could find and decided to reduce my SF and replace it with MUFA. The comprehensive panel showed that I was over absorbing and over producing Cholesterol. It seems that now without a statin my cholesterol is above 300 and my first test after I aggressively dropped SFA was 107 which is lower than I seems reasonable. By adusting the frequency of taking the statin my TC 150 ldl 88 and my fasting glucose is 89, it had been in the mid 90’s.
    How did you settle on 25gm of SF?
    I looked at my diet and realized that coconut milk and most cheese are probably out. How do you make curry without coconut milk?
    Thanks for all the info

    • All empirical…25 was just the number I picked based on his goals (wanting to stay in ketosis) and the need to really reduce his SFA intake.

    • Tyler

      I can confirm you can make a pretty delicious curry by using soaked, blended cashew nuts in place of coconut milk.

  • Kathryn

    Thank you for bringing up reducing SFA’s. I probably fall into this camp. I read a lot in the low carb/paleo/keto communities and I haven’t seen this referenced.
    I have a strong family history of type 2 diabetes and have had gestational diabetes. Because of this, I follow a very low carb/cyclical ketogenic diet but my NMR/lipid panels are not good. Almost every low carb expert (Mark Sisson; Jimmy Moore; Dr. Perlmutter) claims that triglycerides will plummet on a low carb diet but mine remain elevated (209). Have you seen this before? Could you provide good questions for me to ask my GP and my recently referred cardiologist/lipidologist?

  • Travis

    Hello Peter, I have a quick question I’m really hoping you can answer. Could being in ketosis and having a high level of blood ketones effect the results of a Blood Ethanol test done like in the case of a DUI? I read it could effect the breath test, but I am wondering about the blood test specifically. Thank you for your time.

    • Interesting question, Travis. You’re not the first person to ask me about this. I’ve also been asked by attornies. The short answer is that I don’t know, but it could be possible. I suspect that the elevated BAL is “real” and only seems confounded by the fact that it’s higher than would be expected by the quantity of ethanol consumed.

  • Matthew Duhamel

    That watch is worth more than two years of my salary.

  • Dear Peter
    Nutritionally speaking, where do you place Bacon now- do you/ your family still eat it?
    Thank you

  • Conan

    Hi Peter,

    I listened to the Tim Ferris interview with interest. You seem to be on a quest for longevity, or at least slowing down the aging process.

    I get the feeling that low insulin and glucose levels seem to be of key interest in your journey. I have been experimenting myself with Berberine, low carb, mod protein and resistant starch for over a year, and the results have been astounding. Would you consider RS a supplement or a food? I know you used RS in the past, but it was not on your list of supplements on the show highlights.

    In regards to testing diet hypothesis, how difficult would it be to employ identical twins with different diets in regards to aging. Using your website and Tim’s and Dave Asprey’s to get volunteers would seem easy.

    All the Best

  • Tarek

    Hi Peter,

    Not sure if this questions has been posed to you before, however, I’ve been following the keto diet for two months now and I’ve run into a bit of a conflict. I am from the Muslim faith, and Ramadan is fast approaching and I’ve been trying to figure out what the best eating strategy will be since I will be fasting from sun rise till sun set for 30 days straight. Any thoughts?

    Best Regards,

    • Not sure I understand the problem. This should make ketosis even easier, as you’ll be fasting all day.

    • Zak UK


      I’ve been following a keto diet for a couple of months and I am also fasting during the month of Ramadan.

      I’m not sure if you have been following keto during this first week however I can tell you that it’s not easy especially if you’re not adapted yet. The lack of energy and dehydration have what seems like a double effect to normally following ramadan with carbs.

      At the same time I’ve dropped from ~14% body fat to ~12% in the the last 10 days or so. I believe there is a talk on the IHMC youtube channel that Peter did where he refers to an experiment he did of staying keto whilst doing an intermittent fast, so this is pretty similar.

      My experience is that you can stay keto in ramadan but if you are working out as well, and you’re not adapted then you will struggle.

  • Mike

    What is more painful, to discover that one is wrong, or that your teachers were wrong?
    What do MD’s with intense emotional pain do?

    I’m worried about the damage a distressed MD can do. Extreme responsibilities should be removed from a people in a bad mental state.

    To anyone who ever reads this: if you ever have to go see a psychologist, make sure this psychologist does not have wrong ideas about nutrition.

    Please, MD’s of the world, open your minds and be more careful.

  • Norm

    Hi Peter,

    1. Can physiologic IR contribute to higher insulin levels over time?

    2. Although fat raises insulin the least but on the other hand can its overload make cells insulin resistant?


    • Fat is only problematic in the context of insulogenic foods. Hence ice cream drives adiposity more than butter.

  • Frustrated

    Dr. Attia,
    When you say this lifestyle works for 70-80% of the population could you explain what you mean by that? Quick run-down here, I’m only 30. I’ve been overweight all my life. I just clocked in at 386 (up 14lbs) after 2 weeks on LCHF (1529 calorie avg – I am tracking on MFP). I’m so frustrated and it’s hard to find a doctor that doesn’t just shake his head at me and tell me to eat less and move more. I think people forget I’m human, simply because of my weight. Anyways, I love reading your blog and I’ll just keep trying. Thanks for all you do.

    • Ellen Urciola

      Dear Frustrated,
      For what it’s worth, I to have been overweight my whole life (250 at one long point).
      I discovered Peter’s blog 4 years ago.
      After numerous trials and tribulations, I am maintaining 209 (not because I want to maintain that weight) but because I constantly have to reevaluate what I am eating too much of.
      What I have learned is the following:

      * I can’t eat any amount of good fat. I seem to lose weight consuming 66% or less.
      Anything above that and I either stall or begin to gain.
      * I need to track constantly what and how much I eat.
      I first did this by hand, but now use an app.
      * I need to feel a bit hungry. This is still puzzling to me, but every time I eat to satisfaction, I gain weight.
      * I have to serverly limit the amount of dairy and cheese I eat.
      Every time I eat more than 1 ounce of cheese or 2 tablespoons of heavy cream, my weight stalls!
      * I am currently following Dr. Eric Westmen’s, “Duke University” diet (it is on YouTube).
      My routine is right for me and it has paid off, no more blood pressure pills, just one water pill, blood sugar is norma and cholesterol is fine.
      I would highly recommend you read through all of Peter’s blog posts, the Duke diet, and all of the low carb blogs out there. Above all, DON’T GIVE UP! Take ownership, do your research and know you are not alone! It is worth it, and remember, it will take time, it took me four years of trial and error and I’m still adjusting. Oh, and remember, the cravings never really go away, so, stay the course until you are where you want to be.

  • Jeanie

    Hi Dr. Attia,

    I am so glad to have stumbled across your website. It gives me some hope that I am moving in the right direction. Interestingly, in January of 2009, after taking care of my father for five years, who was housebound due to a stroke, I decided to get really serious about improving my diet and exercise. My first step was to stop all sodas and added sugars as I tracked my calories and morning temperature.

    I learned that I would gain weight if I ate more than 1400 calories, and I could lose about 2 lbs a month, if I only ate 1000 calories a day, and given those numbers, it would seem that my metabolism was low or perhaps there was a problem with my thyroid function. Various Docs over the years have run thyroid tests (my mother had issues and took meds for thyroid dysfunction), but the levels always came back fine. I also learned about Metabolic Syndrome and I had at least 3 of the markers, so I knew I was at risk for many unpleasant things.

    I gradually added aerobic dancing and weight lifting into my exercise/walking routine, and counted calories as I continued to rid my diet of processed foods, and began growing my own organic vegetables, and fruits to eliminate pesticide exposures. My blood pressure was improved, and I was able to stop taking HCTZ.

    After I had lost about 20 lbs, I gradually became more and more tired (the story of the prior 25 some odd years). In June 2012, I began having daily headaches, my short term memory was practically non existent, and I absolutely could not get much done due to extreme fatigue, and my BP went back up and Hctz wasn’t helping much. Long story short – OSA . CPAP / O2 therapy eventually helped me to get back to functioning a bit better. My current Doc suspects that I had actually had the problem for 20 or more years.

    In June 2014, I joined a gym with a swimming pool, since my feet were giving me problems and I had to use crutches. I gradually worked up to 2 hours of swimming (rather leisurely), and began tracking food and fitness on the Web MD app.

    It took 6 months to lose 11 lbs. Since my feet are better, and I really can’t afford the gasoline this year to drive 30 miles to the pool, I am back to walking, dancing/exercise video, weight lifting, gardening and house cleaning for activities. Was keeping my calories at around 1300 and activity level at or exceeding the WebMD guidelines, and started feeling extreme hunger. Weight loss had stalled out for 6 months.

    I once lost 40 lbs in 3 months with a modified Stillman’s plan and swimming, and successfully stayed at or near my high school weight for a few years, before gradually gaining 2 or 3 lbs. a year. So I decided it was time to go lower yet on the carbs. Having just read “The Calcium Paradox” ( my calcium levels had been high since 2010), I had added some gouda cheese, or eggs to my one pat of butter along with a vitamin K2 and D3 supplement (Vit. D was found to be low, but pth normal).

    So I have been gradually cutting back the carbs, and keeping between 50 and 60 total carbs per day, and weight loss has begun again. I need to lose 29 additional lbs. to get out of the obese category per BMI data, and that was the goal I set in January 2015. In 2016, I plan to get out of the overweight category – come H3LL or High Water as the saying goes around here.

    The new research is very exciting to read about. At age 67, I feel I have to do the best I can with what the best guess is now. My grand daughter and I are using Atkins materials to help us, but I am very cautious about saturated fat. I am adding a little more cheese, a few more nuts. I continue to use EVOO instead of saturated fats.

    I was very interested to read about the TG/HDL ratio. From 2011 @ 4.7 to 3.02 in 2014 I can at least feel good that an important indicator has improved. I hope the trend holds for the next lipid profile due later this year. I will be talking about the NMR and VAP with my Doc at my next appointment.

    My grand parents had a small farm, and I remember thinking, when the USDA put out their pyramid with grains at the base, that was strange. After all, that’s what used to happen to fatten the steers for slaughter. I never went in much for grains as a kid, and was always “underweight” being feed cod-liver oil, and encouraged to eat salad dressing on my salad instead of squeezing fresh tomato juice on it.

    Any way, we kinda started the journey toward low carbs the same year and the same way. I’ve had a few roadblocks, and gone about things a bit slower as I have been researching and trying to understand what was happening. I read Gary Taube’s book this year and that was when I realized that insulin and hysterectomy in 1997 were probably 2 big factors in my big weight gain since then.

    Again, thanks so much for putting this info our there for everyone to see and think about. It gives me the courage to stick with adding a little more fat after years of low fat eating and stick to the lower amount of carbs.

    “Being defeated is a temporary condition; Giving up is what makes it permanent”. I don’t know who originated this, but it’s true. Keep going and striving. Best Wishes to all who struggle with weight and other health issues.

    • Jim

      Dr. Attia may simply be just another quack doctor. He’ll likely allow this comment. In other words, he considers the possibilities. If we never consider the possibilities, then we limit possibility. This is what it is all about. Follow the instincts. Everything in life is complicated. Think of how complex it would be to learn a completely alien language and then enjoy a conversation with a 4 year old. Did the 4 year old learn from years of research? Learning is the result of observation, prediction, and testing. Often based on little information. Enjoy your food choices and don’t worry about weight. Health and weight are not necessarily negatively correlated.

  • Zak UK

    Hi Peter,

    New follower here from the UK.

    I’ve searched you site and I wonder whether you have any detailed talks on why some people seem to have more success becoming lean (from an aesthetic perspective) on a Carb Cycling or Timed Carbs style diet than on Ketogenic Diet?

    I’ve been on Keto for a few months and I notice some others having more joy despite eating more carbs.

    Apologies if this has already been answered or if it seems like a silly question.

    • Not a silly question at all, but not one I can answer in short response. Best reserved for a podcast.

    • Jeanie

      I am new here too. I posted a comment 4 days ago, and on my computer, it still shows as waiting for moderation. I was wondering if you can see my posting just above yours or not? Thanks.

  • Norm

    Hi Peter,

    With regards to Tarek’s comment above about fasting and ketogenic diet, just to add that the fasting Tarek referred to is even without water or any other fluids. It comes to around 18 hours in UK per day.

  • Zak UK

    @Jeanie yep, I can see you comment.

    • Jeanie

      @Zak UK, Thanks for the reply. I appreciate it.

  • Have you tried out, or taken a good look under the hood of, Metabolon’s Quantose IR testing? They are right down the street from where I used to work.

  • William E

    You want to have a look into that:

    “Similarly, most peoples’ bodies will turn to blobs if they eat almost any carbs (45%) or almost any fat (39%). This is why the holy wars between paleo and atkins people are so intense. They don’t realize there really are at least two correct diets to belong to… for two distinct classes of people. Researchers have found that people who do the diet that’s matched to their genotype (for the 5 best markers scientists know of today) can lose weight 2.5x as fast as those on the opposite diet. Stanford is replicating the study right now.”

    Wondering how much credence you’d give to this piece of evidence.

  • Pkash

    I have noticed that going on a low carb diet got my libido to zero!! what are your thoughts and experience around libido and erectile dysfunction on a low carb diet?

    • Martin

      Foods like beef, fish, oysters, eggs with extra fat from coconut / olive / butter should actually boost your libido. On the other hand if you are reducing calories (i.e. low carb but also low fat) and losing excess fat your body may naturally lower the libido. So eating good food but also eating enough of it should work.

    • Richard S.

      Got to agree with Martin on this one. And Mark Sisson. Eat more saturated fats. Lift heavy things. DO some strength and speed exercises to the maximum. Work out around other men when you can. Alll those are shown to help T, and libido.

  • Maximilian

    Hello Peter!
    Do you have an opinion on the social implications of a ketogenic diet? I am asking, because the media tends to report a lot on overfishing, antibiotics in raising livestock, methane emission by livestock, long-distance food transport/CO2 emission. Which types of foods are healthy and environmentally acceptable in your opinion? Are Avocados and Coconut oil the way to go?
    Since you have a very differentiated opinion on many health related topics and since your are a regular reader of the NYtimes (according to your twitter profile), I guess you have already thought about the aforementioned. I would love a podcast, post or comment on that matter. Thank you very much in advance.
    Kind regards and thank you for the great blog,

  • Andy

    Peter, maybe because the kind of work you’re doing is so awesome, I keep finding myself pushed to share stuff that may help you along the way, plus thinking about themes around it. Below a bunch in no particular order of importance:

    1) Watching your TED Talk I realized something: you are one of the very few people I know who overcame attitude polarization (a type of confirmation bias) and got to the point of publically saying, in the middle of one’s successful profession, “you know, maybe I’m wrong about what I’m doing and my beliefs”. And instead of going to the opposite side, you paused and said “actually, we don’t really know what’s going on and we should stop and try to find out first”.

    Please accept my deep respect for your attitude.

    2) Recompress your blog jpgs or convert them to gif. Two advantages: you save bandwidth money right away, and you lower your bouncing rates (higher loading time drives more impatient people away). You can reduce size with no loss of quality at all. Many software for that depending on your OS, also online tools.

    3) You said people normally get into nutritional ketosis in some weeks after they started for the first time, but you, on the other hand, seem to get back to it in a couple of days after a desert binge. Would you say NK works a bit like a muscle, in the sense that the more the body is used to getting into (or staying at) this metabolic route, the faster it is able to click back into it when starved from glucose?

    4) In some comments in some post, and maybe by you too, I saw criticism about studies in mice, as if implying that they are meaningless to extrapolate data to humans. My impulse wasn’t to join and laugh and agree. Up to now, I’ve always thought that although you can’t directly extrapolate mice results to humans, they should be close enough, because after all we are evolutionarily very close to mice.

    Two points from this: one, are mice results that bad, really? Is a clinical trial in rats worse than an observational study in humans? Two, and here I want to tease you with an idea:

    I’ve watched TED talk from “Barbara Natterson Horowitz: What veterinarians know that doctors don’t”. Long story short, she started noticing enormous parallel between animal and human diseases, and found that many of the “discoveries” we make to treat humans had been already discovered by vets years before. And she started looking into vet literature for hints of how to translate that to humans, and to put vets and human doctors in contact, which generated a lot of insights and new treatments.

    What is it that we already know about animal nutrition, obesity and IR in animals as well as their treatments that could translate immediately for humans and we are massively overlooking it because of our views of vets as “inferior” and because we (mistakenly) think of non-humans animals as being a world apart from humans?

    I recommend you watch the talk and maybe contact her. And yes, I’m suggesting (as she would) that you talk to selected vets or go to a veterinarian convention, raise your hand, and say “Hi, folks. I’m looking deep into human nutritional and insulin resistance, and we need all the help we can find to solve this problem. What is it that you, vets, already know about this problem in animals, how they vary between species, and how do you treat it?”

    If you think about it, it’s not half as crazy as it first sounds, and may give you insights, good questions and good answers that you may not have had otherwise.

    All power to you.

  • Norm

    Hi Peter,

    Is the requirement of dietary protein really this low for maintenance and growth- about 7-10% on a 2500 Kcal diet?

    • Richard S.

      I found like talk by Dr. Layman very helpful.

      I’m a 60 your-old man with inconsistent exercise habits/schedule. I’ve been trying Dr. Layman’s suggestion of getting 30g of protein per meal, and I think it helps.

      (For example, I’ve been injured for the past month and not able to do push-ups. Yesterday I dropped down and dis a set of 40, which is the same number I was doing before I got injured. I’m just a sample of one, but I buy his suggestions about protein.)

      RIchard S.

  • Richard S.


    How valuable is the TG/HDL ratio as a proxy for LDL patterns?

    For example, my doc doesn’t think I need an LDP-P or ApoB test, even though he’s concerned about my TC and at 250 and my LDL at 166. On a LCHF diet I’ve dropped my TG/HDL ratio to 1.6 (111/66), so I’m thinking (hoping) my LDLs are of the fewer, larger type.

    Do you think people should use or rely on the TG.HDL ratio? Or should we all get tested for LDL particle counts?

    (I’ve also had high Lp(a) when not on statins. Don’t know how much that supports a “do the particle test” answer.)

    Thanks for all you do!


  • Matt

    Dr. Attia:

    Great to see a terrific new post! Your reference to cognitive bias and your friend’s book recalled Nobel-winner Daniel Kahneman’s work (“Thinking Fast and Slow”). His research on judgment and decision-making errors is fascinating and indispensable.

    “Ego depletion” is one research area. Various methods are used, but essentially, subjects engage in rigorous mental effort for prolonged periods. Following exertion, some consume meal or glucose-containing beverage. Others get nothing or artificially sweetened drinks. Researchers found that subjects given glucose overcame “ego depletion” and made different decisions. Other subjects remained “depleted”.

    Wondering if you’re familiar with any of this and what you make of it. I’m not an NK dieter but foreswear added sugars and refined carbs. Makes me wonder if avoiding both added sugars AND an all-out NK approach leaves one particularly susceptible to this “ego depletion” phenomenon — Whereas true-blue NK dieters and unopposed to sugary drinks might more easily overcome it.

    Thoughts? Might make for an interesting, peripheral follow-on experiment at some point, if nothing else.

  • Paul

    Dr. Attia,

    I would love to attend a live lecture/talk. Do you post a speaking schedule or is there somewhere I can buy tickets?


  • Anna

    Hello , do you think that it is possible to play professional tennis on ketogenic diet ?? With all bursts of energy and need for quickness. I am a tennis player and I have hyperinsulinemia and I really want to try keto .

  • Greg

    I’m starting to see more articles and research swinging the pendulum towards carbs (e.g. carbs made us smarter as a species), as crazy as that sounds. To be honest, I’m starting to think that health may really just involve eating less food (regardless of its composition), and maybe with that, periodic fasting. Perhaps the low-calorie acolytes of the last decade were on to something.

    • Perhaps, though just how much caloric restriction (CR) is a question and whether the benefits of longterm CR are greater than or less than the longterm risks (I think the in the longrun the risks are greater of prolonged CR). But the more interesting question may be around IF or other CR-mimetics.

  • DT

    I just saw this ‘metabolic ward’ study published in Cell Metabolism, and I wanted to make sure you saw it too. I wish they had implemented a truly low-carb diet (<50g/day) to do this comparison, and they tried to project such results via mathematical modeling, but it's still worth a read. I'd love to know your thoughts.

    Hall KD, et al. 2015. "Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity." Cell Metabolism; ePub ahead of print.

  • Richie Graham

    Have I missed it somewhere, or has the question already been asked?: have you read the NIH study that’s being characterized by the press as a vindication of low-fat diets, and, if so, what’s your initial reaction to it? I read Kevin Hall’s article in Cell Metabolism and noticed the low-carb diet wasn’t a very low carb diet, and was very short-term. I gather that most of the conclusions about the long-term effects were based on computer simulations extrapolating forward. That said, if their methods were sound, it was a surprising finding. I did notice that the lipid profiles were better for the low-carb group if you think high HDL and low triglycerides are more important than low LDL. I’m also intrigued that Kevin Hall is also one of the investigators on NuSI’s Energy Balance Consortium.

    • “I read Kevin Hall’s article in Cell Metabolism and noticed the low-carb diet wasn’t a very low carb diet, and was very short-term.” You can say that again.
      “I gather that most of the conclusions about the long-term effects were based on computer simulations extrapolating forward.” Correct. You know what George Box said about models, right?

  • jesse

    dr attia,
    hi, i absolutely love your stuff,
    i’m an e.r. doc, making my way back from 9 years of diabesity, now getting well thanks to low carb/high fat / intermittent fasting.

    i have fasted as long as 94 hours so far, on bone broth and water, and in three months – have dropped 30 lbs, and lowered Hgb-A1c from 9.0 to 5.6, and dropped hs-CRP from 3.6 to 1.5, and come off of insulin, actors, and metformin. 🙂 and feel GREAT.

    friday, i am going to the sports physiology lab, at the local university, for a modified vo2-max testing
    a vo2-MIN testing, if you will. (they don’t have the hood thing / isolation room for a 24 hour measurement.

    instead of pedaling the bicycle, i’m gonna lay comfortable and still, on a gurney, and try to NOT think about anything.
    it will be a short 30” assay, after 15” of equilibration,

    goal is to get a rough idea of what my (currently) generally sedentary kCal/day expenditure is.
    this will kinda just count the calories of breathing, heart beating, blinking, etc.

    to that, i can then add some data from the fitbit thing my wife bought me for Christmas, but i have never used, till tomorrow.
    and also add in estimates of calories from time x distance walked, cycled, etc.

    just wanting to get a reasonable of where my general caloric needs are for intake, since i still have a lot of calories stored from years gone by that i want to get rid of

    would it be better to approach this fasting? or fed?
    for best applicability?

  • Steve Traversari

    Hello Peter, since I discovered you I can only describe it as amazing! Thank you for what you do and I trust that one day the world will be able to benefit.
    My question/ask of you is with regards to the use of statins for primary care/intervention to prevent CVD or CHD (I presume these two terms are synonymous). I believe the data leading many doctor’s belief that taking statins by those with ‘risk factors’ is preventative toward CVD/CHD is at least highly questionable and potential wrong. What is your view? Thank you.

    • Very important and complicated question which I can’t answer in under 2000 words except to say that both extreme views are wrong.

    • Steve Traversari

      Thanks. Perhaps the matter can the subject of the next blog entry?

  • Pingback: Is Ketosis Sustainable? | Asking()

  • Ethan

    If this topic has been discussed elsewhere I would be happy to be pointed in the direction of good reading material.

    I followed a very strict ketogenic diet for about half a year and then continued a semi low carb diet for the last year. One of the most shocking changed I have observed is about hunger. I don’t get hungry in the same way as I used to. When I ate Honey Nut Cheerios and Mountain Dew for breakfast, I could not focus by the time 11:00 came around because I knew lunch was coming. One and a half years of low carb later, even after a relatively high carb breakfast (e.g. oatmeal), I can skip lunch and still function. Something has fundamentally changed with my body

    FYI I been lean my whole life and my weight did not change through experimentation, just hunger.

    So my related questions:
    What biochemical mechanisms regulate hunger?
    What part of my metabolism changed before/after this diet experiment?
    Why could I not focus on math when I used to eat loads of sugar?

    p.s. I am an undergraduate in biochemistry so this stuff if fascinating.

  • Frances Katrishen

    You mentioned in one of your Podcasts that post-menopausal women are in their own class when it comes to weight loss. I have read most of the major books on the subject of Ketogenic diets. There is lots today about the experience of athletes and obese people. But, there is almost nothing about the unique struggles of many, many women who can’t lose much weight once they go over 50 and their hormones change. Where can I find more information?

    Here is my case: I have been on the Atkins diet for 1 year. I lost 22 pounds in 6 months and got to a normal BMI. Then the weight loss stalled. I was 20 pounds from my weight 5 years ago prior to a gelato and pasta binge in Italy. In the past year, I have had no sugar and no starch and never more than 35 net carbs. I have tracked my calories off and on usually staying between 1500 and 1800. At 5’10”, this is not a lot of food. I have exercised consistently but only moderately. I got just got a Ketonix so I am tracking that too. It measures that I only produce moderate Ketones. Would love it if you posted more on the what you refer to as a unique class of dieters: post-menopausal women. Thanks. Your blog has been a big help.

    • I’m hoping to address this, at least in part, in the book I’m working on.

  • Frances Katrishen

    Thanks, I am looking forward to reading it. I have a Ph.D andI very much like your writing and podcast because all of your statements are based on research. You are doing a great service for many people struggling with health and weight issues.

  • yaakov

    is there any estimated time you can tell us about the finishing of your book?

  • Stephen

    Objective: To find the effect that having a cheese omelet of two eggs per day for breakfast along with a low carb wrap has on triglyceride and HDL levels.

    Design, Settings and Participants: One subject (Me) will eat said cheese omelet every day for over two years.

    Main Outcomes and Measures: Participant will have a blood test after a period of over two years, and compare his blood test from 2/28/13 to the blood test on 10/08/2015

    Results: Participant’s Triglycerides were 73 and HDL 46 in 2013. His LDL was 99 and total cholesterol was 160.
    In 2015 his Triglycerides were 74, his HDL was 47, his LDL was 114, and his total cholesterol was 176.

    Conclusions and Relevance: one cheese omelet a day for breakfast had no negative effect on participants HDL and Triglycerides levels. A higher LDL and Total Cholesterol level were observed, but their relevance has not been determined in heart disease.

  • CBH

    I heard you mention in the podcast that you read several papers on keto and the like per week, thought you might find this paper from Medical Hypotheses interesting. Ketosis may promote brain macroautophagy by activating Sirt1 and hypoxia-inducible factor-1***

    In addition to a nice discussion of the possible reasons for neuroprotection and ketosis, it outlines a few ideas regarding intermittent ketosis and fast induction of ketosis. They even threw in a bit on drinking jet fuel. Your readers might find it interesting as well, so I’m posting it here.

    ***I’m not one of the authors, just an interested medical student. By the way, have you ever spoken at the Cleveland Clinic medical school? Because, if you haven’t, we would love it. You know, when you have a ton of free time and feel like dropping in to enjoy the weather.

  • Peter Berntsen

    On LCHF for 3y, eat a lot of saturated fat as butter, meat fat etc. A recent lipid profile test shows I have LDL-c 8.1 and TC 10.5 , TG 0.8, and HDL-c 2.0. (mmol/L). Practice intermittent fasting 16:8 most days and 24h water only fast some day per week. I will test to eat more MUFA to bring down my LDL levels.
    However, there is a large variation in the cortisol stress response among individuals. My hyperresponsive LDL to saturated fat might be related to a broken HPA axis function and overproduction of cortisol due to too much stress on my body from the intermittent fasting that tip me over in a life as researcher in a new country and establishing a family…? Cortisol is synthesized from LDL thus an overproduction of cortisol can increase the circulating LDL levels? Any studies that has demonstrated such interrelationships?

  • Peter Berntsen

    Addendum. Two weeks ago cardiography showed I have a sclerotic aortic valve. Induced by my lchf eating? I will never know. Put in heterozygous factor V leiden and allergy in the ring too and it starts to be many factors that can contribute to structural changes in my 41 y old heart together with perturbed LDL-c levels. We all break at some point.

  • Dan

    Hi Peter.

    Really glad you posted this story about your patients LDL-P and SFA intake. I found it very interesting.

    This may be a stupid question….so apologies…

    Have you seen any relation between a persons LDL-P reaction to large amounts of SFA and the amount of physical activity they do? You seemed to be able to tolerate huge amounts of SFA when you were permanently in keto but were also doing huge amounts of physical exercise as well.

    I was just stupidly wondering if there could be any connection..

    • Not a stupid question at all, but I haven’t seen a large enough sample size (or study data) to even form a speculation.

  • Dare


    What are your thoughts on the latest WHO statement about red meat:

    Maybe its time for another article to debunk this, like you debunked the cholesterol dietary guidelines?

  • Joseph Fleming

    Hi Peter,

    Thanks for all your research. Are you familiar with Jonathon Sullivan MD, PhD and his article on strength training and health? Here is the link.
    Any thoughts on this as always very much appreciated.


  • Iliya

    Hello Dr. Attia. I’ll get a bit off the current topic and I hope you don’t mind if you read this. Last 2 years I’ve gained a lot of weight . From 70kg to 89 in just 2 years. From lean person to obese. I went to doctor and after a lot of tests they concluded that everything is fine with my health only my tryglicerides are high I think 137 or something like that and my doctor suggested me to reduce the fat in my diet and than I remembered a TED talk I watched some time ago. Luckily I managed to find your blog. I choose to give low-carb diet a chance. I started 2 days ago but I feel so hungry although I eat more fat, I also feel very weak. Is that normal when changing the diets from low fat to low carb? Or is it just not for me?

  • Duncan

    Have to say your interview on the Tim Ferriss show and how you described the taste of ketones absolutely hilarious.
    “I couldn’t design anything that taste worse than this”

    • I wasn’t kidding. The BHB ester is so amazingly horrible tasting it’s almost amusing.

  • David Boyle, Ph.D.

    I am Director of Behavioral Health Science and Professor of Clinical Family Medicine in a Family Medicine at LSU – Health – Shreveport at Conway. I have almost memorized all of your presentations on YouTube. Thanks for all of your work thus far. I totally believe in what your are attempting to do. But, I have a problem when working with patients and residents. I can get the patients to acknowledge the importance of a good diet (like you have outlined) but I struggle to find a way that will motivate them to actually implement the new diet. I have run out of ideal (from a psychological stand point) on how to get patients to actually “change”.

    Can you suggest any methods (anecdotal or empirical) to help incorporate “knowledge” of what to do into actual “behavior” ?

    Thanks a million,
    David Boyle, Ph.D

    • David, I spend 50% of my clinical time thinking about “efficacy”–what is the right intervention (e.g., with respect to diet, drug, hormone, exercise, sleep)–and 50% of my time thinking about “effectiveness”–how do we translate the right intervention into a sustainable behavior.
      So we’re on the same page. Of course, I could produce another blog as lengthy as this one about my approaches, but fundamentally I believe in the work of folks like Richard Thaler and I strive to help my patients create a better “default environment” to promote the intervention.

  • Evan

    I don’t have facebook (don’t get me started on ‘being tracked’).
    and have no time for that type of social media.
    I miss your blog postings.
    Anyway, can you provide a link to your views on Red Meat (in a way i do not need facebook to access)?
    thank you.

    and PS, did you stop posting articles here?

    • I’ve done so on FB and previous blogpost.

  • Dan

    Not sure if anyone has seen any info about these studies trying to link pollution to metabolic disease, diabetes and obesity? All I have seen is this BBC article so I am in no way saying that there is any strong evidence. Is interesting to me as I currently live in Hong Kong and the pollution here, while not has horrendous as Beijing, can be pretty awful at times. I do worry about what it does to my lungs and avoid training when it is bad but I never considered it could have impacts on metabolism.

  • James Mc Geough

    Hi Peter,

    With regards to both raising your daughter and growing yourself:

    *What skills or habits are most important to living a fulfilling, meaningful life?*

    I’m trying to systematically learn skills like writing, negotiation, mindfulness, communication (understanding & being understood), gratitude, happiness, courage, etc. hoping they lead to professional and personal “success” (or are success in themselves). Skills that make you a more effective human being whatever your approach to life.
    An example of how you may have incrementally trained yourself in a a skill/habit would be great to hear, if you’ve the time.

    Even if you don’t get around to my question thanks for everything you do. You’re work has completely changed the way I think about things and opened my eyes to a more scientific perspective, a la Feynman. For that I can’t thank you enough.

  • Sharon Dupuis-Vasquez

    I’m 61 years old. About 211 lbs. I’m not happy or comfortable (my feet hurt all the time) but my blood work is good, sugar levels normal and have excellent HDL and LDL levels. I play racquetball twice a week (I’m not a novice – I play hard). I’ve been lean (150) and kept it off for a year only to let the weight creep back on and stay with me. My default food is fat and sugar.
    I was born underweight (5lbs) into a world of plenty. Is my brain hardwired to keep me fat? I just want to give up but my feet are begging me. My husband and I love to travel but exploring on foot – though I don’t stop – is getting more difficult.
    Fat and frustrated (self loathing comes to mind) in Selah, Wa.

  • Dan

    Apologies for the length of this post…

    Today I am ending my own (n=1) keto experiment. I am in no way trying to be critical about keto or LCHF or encourage others to quit I just thought I would share my experience and why I have decided that my biomarkers are telling me that Keto probably isn’t for me, at least at the moment.

    Some background, before I started keto I had no weight issues or health issues. I am a 35 year old male with an office job who is also an ultra-runner. I was previously eating a reasonably high amount of carbs but I had been a zero sugar, zero processed food and almost zero pasta guy for 4-5 years. My carbs came in the form of brown rice, sweet potato, veggies and milk. My diet was very low fat and I ran approximately 100-120km per week of hilly trails. I weighed about 135-140 pounds and probably around 10% fat. I decided to give keto a try as I was interested in using fat for fuel and not having to ingest so many highly sugary gels etc. during 100 mile and longer ultras. I had never really had any real problem with carbs but everyones stomach usually gives in eventually so having the ability to fuel from fat and not have to carry large amounts of fuel appealed to me and seemed wholly more logical. So, about 3 months ago (30th Sep) I embarked on my Keto experiment. Before I started keto the last blood tests I had had were about 2 years earlier so tough to compare but the basic lipid profile results were:

    Total Cholesterol: 109 mg/dl
    HDL-C: 43 (somewhat low) mg/dl
    LDL-C: 48 mg/dl
    TG: 41 mg/dl

    About 2 weeks into my keto experiment I decided to get a much deeper set of tests done just to have some benchmark. Yes, it would have been better had I done this before I started and yes, it would have been better if I hadn’t started keto 3 days after finishing a 100 mile ultra…however….life isn’t perfect…so I got the standard lipid profile plus LDL-P and also a set of thyroid tests (TSH, fT4, fT3) just to get a baseline as well as vitamin D as I had been low before.

    Total Cholesterol: 190 mg/dl
    HDL-C: 66 mg/dl
    LDL-C (direct): 104 mg/dl
    TG: 58 mg/dl
    LDL-P: 1471 nmol/L
    LDL-Small:240 nmol/L
    LDL-Medium: 290 mol/L
    HDL-Large: 6317 mol/L
    LDL Pattern: A
    TSH: 0.54 uIU/mL
    fT4: 0.96 ng/dl
    fT3: 2.34 pg/mL
    Vit D: 18ng/mL

    Compared to 2 years earlier these numbers seemed to be worse however it was only 2 weeks after starting a high fat diet and just over 2 weeks since a highly inflammatory endurance event so it was tough to know what was to blame…and I had no previous particle count to compare. My HDL did look better so I decided that the only way to know would be to continue with my keto diet and then re-test a couple of months later…which I have now done.

    In the meantime I tried to get on with life on a keto diet including working, socializing and training. I don’t want to write a huge amount but a few points that people new to keto might find useful:

    1. I didn’t find adhering to the diet particularly difficult. It was slightly more tricky than it might have been as I had to drop red meat (I have hemochromatosis and so until I get my iron levels down I am staying off red meat). I ate a lot of dairy but I have never had any ill effects and that didn’t change. I ate mac nuts, eggs, plenty of green veggies
    2. I have to be honest and say that I don’t feel like I felt amazingly better. This is just my own personal feeling and I know lots of others feel a lot better. I did feel more stable in terms of blood sugar and hunger but I don’t feel like Ive slept any better and maybe slightly worse.
    3. I struggled at first with too much protein but that was easily fixed and I would seriously advise anyone trying this to be very careful on the amount of protein. I would say even more so than the amount of veggies.
    4. Once protein was under control I have been solidly in ketosis for about 2.5 months. I have fasting levels well above 1MM, often above 2. I have post exercise levels as high as 6+.
    5. My main struggle has been getting salt/water balance correct and not letting it slip. I was previously a very low salt guy. Not because I was worried I just didn’t eat any processed food and very lightly salted food at home. I had a b.p. of about 110/65 and so when I went on keto I got very lightheaded and it took me a while to realize that it was the salt and also to realize that it took me multiple days of taking adequate salt to recover from a deficiency. I thought that if I took a bouillon cube with water it would suddenly make me feel ok. My experience was that it didn’t but that over a period of 2-3 days it would resolve. I also made the mistake of taking lots of salt and not enough water. This just dehydrated me and jacked up my heart rate. Then I did the opposite of too much water and not enough salt…that just causes nasty headaches! 🙂 I would say the best is the same as Peter suggests…just build in a couple of cups of bouillon every day into your schedule. Living in Hong Kong didn’t help so much as you lose a lot in sweat outside and the buildings are heavily air-conditioned (so cold that you need sweater inside) so you lose a lot of water.
    6. My training was very tough. heart rate higher by 10-25 beats for equivalent exertion. I found that ensuring I was taking in enough water/salt helped and that it did improve but I have not been able to get a really consistent month of training whilst on keto to fully get my body adapted and make it work. I did a metabolic test and found out my RQ at different HR/pace and I did feel that I got some improvement but I have found that I was struggling a bit with feeling good generally (mainly salt/water issues) to train enough. I believe with time I could adapt and Im sorry that I haven’t done more. My resting HR had previously been about 38-42 and is currently 50-55 but I expect that may also have improved with more training.
    7. I found that on the one occasion I ate too many carbs (brussels sprouts and super starch) and knocked myself out of ketosis. My blood ketone levels dropped to 0.3 around midday but I carried on eating lots of fat and within 2 hours they were back above 2MM. However, I discovered that my body didn’t recover for a few days regardless of what my ketone levels were saying. I was producing tons of ketones but it felt as if by being exposed to too much glucose my body was not utilizing the ketones as much. This was most noticeable overnight after I ate too many carbs at lunchtime. I went to bed with ketone levels of 3.5 after a high fat evening meal and I woke up with levels of 0.8, glucose levels of 5.9 and a feeling I can only describe as a hangover…my ketone levels rebounded quickly after breakfast but it took another day or 2 before I felt better again. This was interesting to me as people often seem to talk as if they feel good once they get their ketone levels back up after being knocked out but that wasn’t my experience. Perhaps it is because I hadn’t been in keto long enough and my body would behave differently after a year or 2. My daytime levels were immediately back up but for 2-3 days I felt bad, my fasting glucose was spiked and my morning ketone levels were lower. It was almost like I had to go back through a few days of adaption and running down glycogen stores but my body was still producing ketones…This surprised me.

    So, I would say that up to today I have had a couple of periods of feeling very good and lots of ups and downs as I try to dial it in and get it right. I definitely feel that getting it right for day to day life is a LOT easier than getting it right whilst trying to train athletically but that is just my opinion. I think I was maybe just bad at getting salt intake correct but when I dropped my training and just tried to live my life things became easier. I had thought of ditching it a couple of times just when I was struggling with lightheadedness that would seem to not go away but I wanted to stick with it and try to make it work for me. I never really craved carbs and have enjoyed the food very much.

    The only thing I wanted to be sure of was that I was not doing more harm than good by adopting this diet and I decided I would be guided by the numbers. I have got to the point of having the salt and other small issues pretty dialed in and I take several ketone and glucose blood readings per day so have been able to understand how my body reacts to different foods. The main issue for me was to see if those blood markers that looked sub-optimal 2 weeks in had got better, worse or stayed the same 2 months later. I had not done a lot of heavy training or races so none of the numbers would be skewed by that. I added a few more tests ApoB, HbA1C and reverse T3. I got the initial results back today. I am still waiting for the reverse T3 and the particle count but sadly nearly every single number that I did get so far has got worse..

    Total Cholesterol: 251 mg/dl
    HDL-C: 62 mg/dl
    LDL-C (direct): 163 mg/dl
    TG: 80 mg/dl
    HbA1C: 4.7%
    ApoB: 149 mg/dl
    Lp(a): 3.4 mg/dl
    TSH: 0.75 uIU/mL
    fT4: 0.94 ng/dl
    fT3: 1.96 pg/mL
    Vit D: 38.5ng/mL

    The total cholesterol increase and LDL increase I was less surprised about and by itself I wouldn’t worry but with an ApoB of 149mg/dl I expect the particle count to also come back very high. Another thing that I was surprised by was an increase in TG from 2 months ago, which was already an increase over my low fat diet. I really hadn’t expected worse TG. There is a slight change in thyroid numbers but I honestly don’t have any symptoms of thyroid problems and was mainly getting these to check. My Vit D numbers improved which just showed that my 5000IU supplementation had helped.

    Given the fact that a) I had pretty decent health and biomarkers before I started keto. b) I had no signs of metabolic syndrome or any issues with carbs in my diet. c) since starting keto many of my biomarkers appear to be going in the wrong direction. I feel like I have 2 choices.

    1. Try to continue with Keto but drop my SF intake and replace with MUFA (I am obviously aware that people have had success with this).
    2. Try moving back to something closer to my old diet with more carbs and less SF

    I have decided to go for option 2. If I had any metabolic issues before I started then I would think it worth trying to make keto work but I was doing this as an aid to my training/racing and it seems to me that this diet is probably not the one best suited to my genetics/metabolism. I was really hoping I would have numbers like Peter whereby my SF intake had only +ve effects on my lipid profile but thats not the case.

    I don’t believe that my experience means keto is dangerous. I don’t believe anyone else should use my experience as a reason not to try this diet. I do think that I will still incorporate more fat in my diet than I did before I started keto (butter, animal fat etc.). I do think everyone should make their own minds up about their diet and not try to be pigeon-holed into what someone is telling them. I do also think that having the appropriate tests to really see what your body is doing is important to help guide decisions.

    If in 1 year, 2 year, 5 years time we are able to understand the cholesterol profile changes I have seen and we are able to either scientifically explain them as safe or understand what causes and how to prevent them I would definitely try a keto diet again. I may also want to try it again if my body starts to show metabolic issues with carbs. If that happens then I will be optimizing for something different. I may be willing to be more restricted in my eating to stay in keto. For now I plan to switch back to my previous diet by adding more carbs to my diet in the form of veggies, sweet potatoes and maybe some rice and remove some of the saturated fat from cream and cheese and then re-test in 2 months.

    I do feel sad to be changing my diet but I think that is mainly because I saw such potential and had spent 3 months struggling with it and learning the ins and outs. I hope I can incorporate some of what I have learned into my new diet, even if it is not a full on keto diet.

    I find the whole subject of nutrition extremely interesting so I will definitely be continuing to read this blog and other sites to learn more from other peoples experiences.

    Tsk again Peter for all the time you spend on this site. I have found it an invaluable resource.

  • Willie Wilson


    Regarding this: ” I realize there is a contingent within the LCHF community who argue that traditional biomarkers of coronary risk—such as LDL-C or its superior cousin LDL-P—“don’t matter” if one is on a low carb or ketogenic diet”

    I have actually not seen discussions specific to LDL-P not being important. Actually, I have seen the exact opposite in the LCHF community. I am LCHF and my LDL-P spiked and had to reduced my SF intake and rebalanced the Fat and protein mix and they have reduced significantly.


  • Christopher

    Hi Peter,

    I have come to suspect that I might have a rare disease called hereditary fructose intolerance (HFI) in which newer evidence suggest that both heterozygotes as well as homozygotes suffer from an deficiency in fructose metabolism, leading to a paradoxical reaction of hypoglycemia after ingestion of sucrose, fructose and its cognate sugars. I´ve tried reaching out to Dr. Tolan of Boston Uni. ( before going to my physician next week in order to convince her of doing a genetic test for this condition. There are other diagnostic tests (fructose challenges) but for homozygotes of HFI they are risky, i.e. sufferers are reported to have died from I.V.´s containing fructose and sorbitol (a cognate sugar).

    I thought you might find this topic interesting considering your involvements and interests you´ve shared on this blog as well as NUSI, so I just wanted to let you know. Also, I am no scientist so I believe you are much better off researching (if needed) aldolase B deficiency ( – I know wikipedia is a terrible source, sorry) yourself rather than me trying to explain it to you in detail. But, I was wondering if synthetic ketones or perhaps MCT-oils might get around how this deficiency kills people (hypoglycemia due to inhibition of convertion of glycogen to glucose, in my simple understanding) and perhaps be life saving for sufferers of HFI?

    I would love to hear your thoughts on this, and I hope you find the subject interesting. There is so much we don´t know about sugar metabolism, so I hope this rare disease might be a way to learn more about it.

    Thank you kindly,

    Christopher N.

  • Richard

    Peter, you’re very busy. But we still miss your posts. 🙂

    You said you had a few dozen topics to write about. Maybe put 1 to 2 days aside and deliver at once 3 to 6 posts you think should have been written? There must be some that are high value but quick. Or some short and to-the-point summaries.

    Imagine seeing them published and everyone happier and healthier? 🙂

    Hapy new year!

    • Richard


      Posts I’d love to see and believe, from your previous comments, that you’d like to write about too.

      The straight dope on Fasting (intermittent, multi-day, how-to safely, benefits and risks, using it to help get into NK, etcetera).

      Appetite regulation.

      Effects of caffeine and alcohol on insulin sensitivity and NK and how to minimize bad effects through dosage and timing.

  • Hakim

    Happy New Year. We miss your writing or podcasts. Hope all is well.

  • Christiaan Ferreira

    Sorry, how does one convert g/L apo-B to the nmol/L units you used?

    • No conversion, totally different measurements.

    • Christiaan Ferreira

      OK, OK, technically that’s true Peter, but surely you know what I mean? Let me try to be more punctilious: when I measure Apo-B, in g/L (or mg/dL),
      how can that give me an idea of what my LDL-P is, in nmol/L?

      I got something of an answer in a Varvel, Dayspring et al. article. To be sure, the article looks at cases of discordance between Apo-B and LDL-P (while noting their strong association), so we need to assume that there is no discordance (e.g. not many small particles and not a lot of Lp(a):

      “Although there is no formal standardization program
      for LDL-P,
      it could conceivably conform to the apo B LSP,
      by adding the VLDL particle number to the LDL-P and converting nanomoles per liter (nmol/L) to mass units (mg/dL) based on the molecular weight of apo B (550 000 Da) (49). This conversion recognizes that both total plasma apo B and LDL-P measurements presumably include IDL and Lp(a), in addition to LDL.”
      – Varvel, Dayspring et al.

  • Eric

    Hi Peter,

    Hope you and your growing family are well.

    I recently started supplementing with Berberine since you mentioned it on your Tim Ferriss interview. And I have a motto that anything Peter Attia is willing to put into his mouth … I’m at least willing to try 🙂 (But seriously, I respect your judgement)

    I’m wondering why you chose Berberine over Metformin for your own personal choice. Being a Doc I assume you could get easily get a prescription for Metformin.

    Metformin would seem to have a much longer history than Berberine for blood sugar control and and has been studied more extensively. (Hence maybe safer?)

    I have concerns over long term use of an Herb which hasn’t been studied that much, but I probably can’t get a script for Metformin since I’m not diabetic.

    Thanks and best regards,

  • Mike

    Hi Peter,

    I’ve found some interesting information/research on goldenseal and its predominant and most active alkaloid berberine. It looks to me like there is a significant danger of carcinoma/adenoma in the commonly used dosage range for hyperglycemia.

    Let me summarize first. In the 2010/2011 timeframe a long term 2 year rat/mouse study was undertaken by the National Toxicology Program at NIH. They ran 2 week, 3 month and 2 year studies. Liver Hypertrophy was found in both the 2 week and 3 month trials but the 2 year trials showed even more significant damage.

    In the two year study male rats fed 25,000 ppm of goldenseal powder ad libitum showed a 20+% incidence of liver hepatocellular adenoma or carcinoma. This was the most signifcant effect. The concentration of berberine in the goldenseal powder was 3.9% by weight. When all the calculations of converting the amounts taken daily by the rats to a human equivalent dose are done it turns out that the rats with the 20% rate of carcinoma/adenoma were consuming the equivalent of a 100 kg human consuming @880mg/day of berberine. Interestingly there was no carcinoma in the female rats and only 2 with hepatocellular adenoma.

    Jumping from goldenseal powder to berberine as the culprit is a big jump but reading the paper you will see that the researchers, even though avoiding saying it was definitively berberine that was the cause, did talk a lot about berberine in the discussion.
    That first paper is here:

    Subsequent to the paper and motivated by the paper a second in vitro study was done to try to ascertain how that cancer in the rats might have been caused. In that study the researchers examined 5 alkaloids from goldenseal and found two that were active. Both were topoisomerase I and II interruptors and the researchers felt that this may have been the cause of the cancer in the first experiment. One of those alkaloids palmatine was of much lower concentration and somewhat weaker than that of berberine.
    That paper is here:

    As I said the NTP of the NIH actually ran 3 different trials. A paper containing all the work is here: (190 pp)

    There is a summary of the long report immediatley above here:

    I know it is difficult to get supplements tested but it certainly does seem that another longer term in vivo study of berberine itself is in order. Berberine has become a very popular alternative to metformin and more and more diabetics are taking it. It seems particular risky when considering the fact that the dosage range that appears to have caused cancer in the rats is the same range as many are taking for hyperglycemia on a daily basis.

    Since I think the first thing you will want to check is dosage here are my dosage calculations taken from a forum post:

    The weight to weight mg/kg ratio is designed to eliminate the need to take into account the individual weight of the differing subjects. When the number of 54.6 mg/kg (from the research) is cited it means that the animal is consuming his own weight * that amount in berberine as a constituent of the total Goldenseal added to the diet which is 3.9% of the total Goldenseal. If the rat weighed 1kg it would have consumed 54.6mg if it weighed 0.1 kg it would have consumed 0.1 * 54.6mg or 05.46mg.

    Now let’s move to humans. If we had a 1 kg human being they would consume exactly the same as a 1 kg rat or 54.6mg. If we had a 100kg human they would consume 100*54.6mg or 5460mg.

    Because animals have different consumption rates depending on volume:weight ratios experimenters adjust dosages according to those ratios. For rat:human that ratio is 6.2:1 meaning a rat has to consume 6.2 times as much as a human per kg of weight to get the same effect from a drug. Therefore to get the human EQUIVALENT dose the rat dose is divided by 6.2. 5460mg/6.2 = 880mg or slightly less than 2 500mg caps for a 100kg human. 100kg=220pounds.

    Clearly this dose of 880mg is well within what is considered “therapeutic” by the mfgrs and consumers of berberine.

    Peter, I hope you can find the time to read and think about these results. I think a long-term in vivo study is needed for berberine preferably with a large cohort divided as to time of sacrifice into shorter periods to better assess when and how much impact there is. Maybe transgenic or xenografted mice would be an option as well.

    Best regards


  • Steve Stephenson

    Your post: “In one particularly interesting case, a patient in self-prescribed nutritional ketosis presented to me with an LDL-P of more than 3500 nmol/L …”

    Had he reached a stable weight for weeks or months? At, Dr. Phinney says adipose tissue floods the blood with stored cholesterol as it loses weight (by shedding cells emptied of TG?), which the liver dumps into bile in the gall bladder, thus into the gut and out of the body with the stool. Once the person’s adipose tissue had “cleansed” itself, the LDL levels reduce markedly.

    Another question: for a person whose prostate is a mass of scar tissue from radiation treatment would a very high LDL-P (2558 nmol/L) indicate that his body is trying to heal itself using the cholesterol? If so, wouldn’t it thwart the body’s efforts by treating the very high LDL-P with statins; or by reducing dietary saturated fat as you propose?

    Related question: does this study say statin use is indicated for post treatment prostate cancer, Does it matter that it seems to be funded by industry?


    • That’s one hypothesis. It’s certainly possible, but I wasn’t about to wait around to find out.

  • John

    In your Talk 1 commentary above – what would a diet look like for your experiment patient, higher MUFA, lower PUFA and SFA? More olive oil, avacados, less coconut oil?

  • Tim

    Hello, a couple questions Ive had trouble finding information on:
    Why do type two diabetics have higher rates of gluconeogenesis, wouldn’t blood glucose levels (if high due to insulin insensitivity) repress this process?
    Regarding ketosis, ketoacidosis will only rarely take place in other than type 1 diabetics due to the ability for even minimal insulin production in healthy individuals and DM2’s. In ketosis, the body would produce insulin (preventing ketoacidosis) in response to higher ketone levels and thus repress ketone production, or insulin would only be triggered by protein intake? Thanks so much if you have time to respond.

  • Martin

    Peter, is there anything going on around Nusi that might be worth sharing?

    I’ve checked the site:
    – the latest News updates date back to August 2015, these are links to an articles by Gary Taubes (not really news) and a mention of Framingham study.
    – under Initiatives, only the Fr. study is mentioned, at the website it says: “This study is currently recruiting participants”.

    Nusi was launched in Sept. 2012. Sure, it takes time to prepare scientific studies well, but how much effort would it cost to publish some regular updates, esp. since none of this were possible without GT’s books winning lots of public (=our) attention & support 🙂

    • I’m no longer at NuSI.

    • Martin

      Thanks, it is an interesting update.

      I’ve just listened to the latest podcast on Chris Kresser and it seems you’ve moved beyond the war on insuline and simple diet/weight loss issues. On a personal level your new(?) direction makes perfect sense to me!, I’m also no longer interested just in dieting for fat loss or sport performance for this moment, but now that I’ve moved past 40, my goal is to be able to practice my sports (climbing, running, sailing) with my kids in the next 10, 20, 30, … years.

      I’d still have one more question if you don’t mind: do you still consider your goal to affect the public policy, to potentially help people like those your mentioned in your TedTalk? Or have you got disappointed/disillusioned with the system and see little chances of changing it? I have really no clue on the actual state of NuSi, but it seems the progress hasn’t been dramatic. I might be wrong, I hope I’m wring.

  • Roman Watkins

    Re-updated –
    Evidence for (and against) the dietary guidelines restricting saturated fat.

    Very interesting read thank you for sharing your update, I have long followed you and your self-experimentation. As an avid cyclist who I’ve always appreciated your posts, especially when it involves performance and low carb. I would really like to get your thoughts (maybe another blog topic) on your 20/20/60 diet and its relationship to your performance. I’ve cycled in and out of ketosis over the years riding up to 600km some weeks in ketosis. I’ve been considering carb cycling or timing based on energy my needs. Any people or resources you’d recommend on this.

    Thank you again

  • Scott Miller

    I’ve enjoyed your blog and learned much along the way. Would consuming exogenous ketones allow one to undertake a multiple day activity like hiking and consume substantially less calories while maintaining body mass? (I hesitate to use the term weight since you have explained well the ebb and flow of hydration). It seemed from your cycling tests that this could be the case?


  • Jacob Anstey

    I’ve recently just started reading your writings and listening to your lectures (podcasts you are in, too), Peter. I must say: Congrats on the self-experimentation and determination to get the results you desired.

    I won’t ask for medical advice, as I know the professional obligations you have elsewhere. However, I was hoping you could point me into the right direction, as it regards to research and self-experimentation. Right now, I am using PubMed through my university and possess no formal background in biochemistry, nutrition, etc. (I’m an ECON major).

    I’m currently 21, but at the age of 15 lost about 120 lbs (272 to 150 lbs) in a span of 9 months. Through that time period, I was diagnosed with an eating disorder and suffered through depression. No sympathy wanted; I am a product of my own decisions.

    Today, I am 21 and have reverted back to the low end of things (am at 143 lbs, roughly 6’1” and got a body fat % at Complete Nutrition that read 4% — unsure how accurate; probably not much). Right now, I am experiencing fatigue and have very dry, red hands. My most recent blood pressure reading was 97/66 and a heart beat/minute of 45. Right now, my morning glucose reading after an overnight fasting period is in the 80-85 mg/dL range. In a sense, I believe I am fairly insulin sensitive.

    My source of carbs right now are oats in the morning, beans/lentils for lunch and sweet potato/quinoa for dinner. No variation from those. I eat berries with breakfast and an apple for dinner. Three meals, one snack before bed. I’ve lost about 15 lbs since September of 2015, but am unsure how much food I actually need to eat just to maintain weight. Right now, I eat roughly 2,000 kcal a day.

    My goal is to gain about 30 lbs of muscle, but don’t know where to start. I understand I have a shaky past with food, but am trying to face my demons and overcome my fears.

    I know you can’t really help, but wanted to get this out there (even if it is very informal). Perhaps one of your other readers can help guide me in the right direction.

    Most articles/blog posts are directed towards individuals on the opposite spectrum. It is quite frustrating trying to find reliable information to help me regain the life I lost.

    I’m on a mission right now. Again, I know you can’t help, but anything would be helpful. No matter what, I am determined not to fail.

    Keep up the good work, and I look forward to keep reading your work in the future.



  • Anne

    Hello Dr. Attia,
    Thank you so much for all the web content. I remember on your TedTalk that you said there are other metabolic disorders other than diabetes Type II that are more “sinister”. Can you elaborate? Thanks!

    • All that follows… (CHD, CVD, cancer, AD).

  • Su-Chong Lim


    This comment is a propos of nothing except a gut reaction of needing to respond to your outpouring of obvious affection for your daughter. She is greatly blessed, and so are you. I recall the raw emotions that were ignited in me by the birth of my daughter 31 years ago, and the many, many interactions that I have tried to have, on an emotional, intellectual and moral level since. Somehow, I managed not to spoil her rotten, but that’s largely my wife’s doing, as she was strict, with very firm boundaries, beyond me at the time, but what I realise in hindsight was essential to hour children’s growth. My daughter realised early on that she could not tolerate the icky biology things that she encountered in school, but which her Daddy insisted on discussing ad nauseum, so rather than pursue the biological sciences, she followed her own path of finding things out by becoming an electrical engineer. So now she is a secure, intelligent, funny, caring, athletic, capable human being who I have no problem leaving in charge of the world she will live in. She just had a baby 3 weeks ago, just at the time when I thought, maybe she’s not her Daddy’s little girl any more. (Please forgive the rather sexist slant here — I have a younger child, an equally capable, compassionate and funny son, whom I love equally fiercely, but, you know, it’s different). From a logical viewpoint, parenthood is the most sacred mission. But it’s the emotional intensity that was the most unexpected for me. Peter, you have absolutely no idea what’s ahead!!

    • Su-Chong, I know the feeling. Daddy-daughter-date-nights are the highlight of my month. I hope you’re right (re: what’s ahead). Seems like it can’t get better than this!

  • Su-Chong Lim


    I just have to warn you, one Dad to another, of one terrible thing that will come. Despite your best intentions and all your heads ups, there will come a day when you will fail her. And you will feel worse than at any other time in your whole life, worse than after your worst clinical misjudgements, worse than…just anything. For me, it was when I joined the parents class at my daughter’s tap lessons. It was quite good at first; I had never danced before, and after a while I even looked as though my kicks weren’t meant to be lethal. At the end of the year there was a recital, and the final number had the whole ensemble, with the whole parent section joining in the back row, with the climax having the parents doing “wings”, except I didn’t realise at the time that what we were doing with our feet was not really the standard stuff (my daughter only disclosed this to me later, to spare my feelings). It was wonderful. There were 2 performances, so we went to grab a quick snack and come back for the 2nd performance. Except I had heard the time wrong, and, cut to the chase, we missed our parts in the finale. I was just devastated. But she forgave me. And that just made me feel lower than dirt. Just letting you know. It’s going to happen to you too, someday, somehow. And there’s nothing you can do to prevent it.

    But, you’ll survive, and next morning, somehow, the world will still be there, and life will restart, after a fashion, and be ok again. Just a heads up, Buddy.

    BTW I also have a nickname for Grandson (it must be a mechanism for veiling our overflowing emotions). They took the longest time finding names that they liked. As her husband is of Scandinavian stock, I decided on Gunnar, and threatened that that would be it, boy or girl. Well, after he was born, they took so long to name him I just kept on calling him Gunnar. So I understand Michael Jackson.

    • If that’s the worst I do, I’ll die a happy man.

  • Run

    I’m one of the “lucky” few that apparently are in this situation. My LDL-P came in at a whopping 3,341 with HDL at 7733 and Tris at 67. As per what was described here I cut back drastically on my SFA and upped MUFA big time. I have some doctors appointments lined up and I’m looking forward to seeing what the results are but, in addition to that my HGBA1C level showed that I was prediabetic too! I was wondering if you observed that behavior in any of your patients… my diet is pretty strictly limited to broccoli, butter, and beef, with the occasional indulgences being low-sugar as well (100% dark choloate, coocnut manna, and So Delicious Unsweetened Coconut ice cream).

    Thanks for this post- it was pretty reassuring to know that I’m not the only one.

  • Malee

    First, let me confess to anyone reading this that I am a bona fide Libertarian Socialist.

    Dr. Attia, I am sure you are probably already aware of the defamation blog posted by Michael Suede (Libertarian blogger – also has a YouTube channel) back in March. Have you had a chance to respond to it? While there are certainly holes in several of the arguments made (and there isn’t much you can do about conspiracy theories, unfortunately), he did cite a lot of research publications, many in which you are probably already well versed.

    I don’t wish to see any unfounded barriers to your research efforts that are inspired by such. Your work is vital work. You promised years ago to “go where the data takes me” and we have faith in you. Please, do not ignore any valid criticisms that may have been addressed here, and do not turn a cheek to slander. You should respond, and do so publicly.

    • The title of his post is “Dr. Peter Attia: Hack, Liar and All Round Disgusting Individual.” Really? Wow, tell me how you really feel. When last I checked someone who opens with an ad hominem attack isn’t worth the ether they occupy.

  • Philippe

    Hi Peter
    Thanks for the great work!
    You recently mentioned berberine on the TF podcast.
    Can you comment on the possibility of berberine causing muscle atrophy (possibly by increasing AMPK)?

    • I don’t think this mouse model is relevant to humans.

  • Dan Walker

    Any quick thoughts on Desmosterol vs Lathosterol to get a snapshot of synthesis status? Also, wouldn’t using Beta-Sitosterol and Campesterol as markers for intestinal absorption be highly dependent on how much plant material is in someones current diet?


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