June 18, 2013


My Quantified Self, Part I

My 2013 presentation at the Institute for Human and Machine Cognition (IHMC): An Advantaged Metabolic State: Human Performance, Resilience & Health.

by Peter Attia

Read Time 2 minutes

In 2013 I gave a presentation at the Institute for Human and Machine Cognition (IHMC) in Pensacola, Florida. Ken Ford, the CEO and Founder of IHMC, is a remarkable person and I could not wait to meet his team and see their research.  IHMC does cutting edge work, primarily for the Department of Defense (DoD). I had an exhilarating day which culminated with a presentation I gave to the team and also the public.

The talk I gave was a first timer.  (Usually the first two or three times I give a talk it’s not very good, as I need to work out some kinks.)  However, since the talk was recorded I’ll set my perfectionist tendencies aside and share it, below.   The talk is about an hour, and the Q&A session was also recorded.

A month or so before the talk, I asked Ken what he wanted me to talk about and he suggested I speak about human performance and resilience – both topics of importance for the DoD.  I don’t consider myself an expert in either of these topics, but I certainly appreciate the need to maximize, or least optimize, both.  Rather than give a highly technical talk, I chose to give a slightly technical talk that focused more on my own journey in this space and some of the experiments I’ve done on myself, specifically those around energy utilization.  This talk does not present all of the data on my self-experiments, of course, but hopefully it gives you a sense of what kind of data can be gathered for studying energy utilization.  In subsequent posts I’ll likely delve further into the data that support these findings and expand on a few of the tangents not fully explored here.  For “regular” readers of this blog, the first half of this presentation is pretty basic, but the second half should offer novel info.  For new readers, hopefully the entire talk will be informative.

For those reading via email, here is the presentation:


Photo by Siyan Ren on Unsplash

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  • Dietolog

    What an amazing talk. Can you elaborate more why commercially available ketone bodies (raspberry something) are crap? What do you expect from a commercial product to be a good substitute for your own ketones?

    • Minimal (if any) bioavailability and quantity. A correctly formulated ketone salt or ester could deliver large does of B-OHB or AcAc to augment nutrition.

    • Krista

      My husband and I recently watched this talk. It was very informative and I am now going without sugar. I am really excited about the change . My husband,who is a triathlete was wondering if you had an increased amount of fat due to a lot of swimming prior to your diet change. How has your exercise routine changed since your diet change? Also you familiar with the China study which indicates that eating meat and animal products is linked to cancer. I would love to know what you think of this. Thanks so much for sharing your personal journey.

      • It’s possible I was storing so much fat because of an adaptation to cold water swimming, but I still continued cold water swimming for long distances a year after my weight loss.

    • Petrolene Le Roux

      I stumbled across this presentation via a tweet from Tim Noakes. I’m no scientist, have limited medical background as nurse and are just starting a career in sports conditioning/nutrition coaching, but this whole thing about metabolic inefficiency and syndrome has completely captured me. I work in a contract research organization where we do pharmaceutical research and most of the research evolves around conditions that contributes to the definition of metabolic syndrome. I’m wondering though – they never capture data around what patients eat during these trials (except for most of the phase I studies where a specific diet is prescribed). How much of the drug effectiveness is really about the study drug and how much might be as a result of a better diet (which the patient might start to follow subconsciously while on the trial). We’ll never know. Just curious.

  • Great talk – though it seems a case of preaching to the converted going by the Q&A, so it’d be nice to get this info out into more mainstream arenas.

    For folks who’ve followed your blog since the start I think they’ll find the first 35 minutes is just trodding over well established ground, but from there things get really interesting with the metabolic ward study stuff – will be good to see how much of the data you can put online for folks to play with – I think it mostly highlights that we still don’t know much about what is going on and how.

    • Yes, good point, Ash. Probably should have made this point. For “regulars” the first half of this talk may be too remedial. Hopefully, if folks are interested, they can stomach it to get the second half.
      BTW – you won’t catch me complaining when I have a friendly audience. It’s really refreshing once in a while. I’m pretty tired of getting yelled at and told I’m an idiot.

  • Ted

    Awesome talk Peter! Really like your stuff and what you’re doing. Keep up the good work!!

  • Butch

    in the Q&A part you mentioned BCAA.

    Can you elaborate a little bit more on your protocol as far as BCAA is concern ?

    When do you take BCAA ? Pre or Post workout ? How much ? Any specific manufacturer you can recommend ?

    Kind Regards….

  • bill

    Two things:

    Where do you get “branch chain amino acids” and what dose?

    Please tell your wife there are many people who are following what you
    do and appreciate it highly and it is helping them/us. And thank her
    for her forebearance. (Urine in the fridge – really!)

    • Thanks, Bill. After my whole thing on NOT saying which BCAA I use because of my brother, you’re asking me, huh? Puts me in an awkward spot. Since you’re the 10th person to ask between the blog and FB, here is the protocol:

      I use a product called BioSteel (http://biosteel.com/product_hpsd.php), specifically (for BCAA), their “high performance sports drink” or HPSD, which not only contains BCAA, but other co-factors that render them more bio-available including glutamine and taurine.
      As I have come to learn in helping my brother due diligence them, they are very unique in this space, as they actually use legitimate BCAA, which most products do not contain. I won’t go into details here, but I would encourage anyone who is interested to reach out directly to them and ask all the questions they have.

      If you’re wondering why their products are more expensive, which I’ve asked, it’s because they use (and can verify) entirely legitimate ingredients. It’s amazing how cheap you can sell BCAA when you sell crushed bird feathers from a factory in China (sadly, this is not made up…the unregulated nature of this industry makes this a very common scenario).

      Protocol: I use at least one scoop of HPSD *during* every single workout I do — high-intensity lifting, swimming, and riding. On the bike, I usually use more than one serving, depending on the ride duration. I always mix one scoop per bottle, but I’ll start with 2 pre-mixed bottles, and bring extra HPSD for re-fills.

      You should discuss other protocols with them directly, if you have questions. Some prefer to use before. I take nothing before workouts, except the occasional bulletproof coffee; I use HPCS (+/- plain super starch +/- nuts during for very long rides) during workouts; and the biosteel whey isolate (http://biosteel.com/product_wpi.php) post workouts (low amount, typically <25 gm).

      Because I know someone will ask... I do not use their advanced recovery formula. Instead I use their whey isolate combined with super starch (i.e., I make my own).

      ****NOTE TO ALL READERS:**** I am not going to answer any more questions about BioSteel. You have all read my disclosure, so feel free to dismiss my use of this product if you think I'm stupid enough to use a product because my brother knows the guys who run the company.

      After getting skewered by so many people for writing openly about super starch last year (again, I have/had ZERO financial interest in Generation UCAN, the company that makes it), I've decided I'll never again do a deep-dive on a commercial product, regardless of how much I believe in it. If you want to know more about BioSteel, contact the company directly.

      I've been working with BioSteel products for several months, and have put every athlete I work with on them, especially the HPSD (i.e., the one that contains the BCAA). If you even partially understand my integrity, that should tell you I personally believe the stuff is superior to any other formulation. Thanks for understanding and not asking further questions.

  • Mark Weaver


    Outstanding talk! I really enjoyed that and learned A LOT. Thanks for sharing.


  • Michele

    Dana Carvey or not..I wish I could’ve seen the laser pointer. It’s a bummer because I think it would’ve helped.

    Even though the first part may be repetitive for some, I found it a great refresher.

    Thanks so much Peter.

    • Glad you caught the joke. Maybe I’ll give the talk again some time, complete with laser pointer and all.

    • Michael Hirasuna

      The Keynote presentation app on the iPad has a built-in laser pointer which shows up on the video.

  • Michelle

    Peter, Thank you so much for taking the time to make all this information available! My goals are VERY different than yours, but I’m still learning from you and your goals (high performance/poor genes). I wish we were blessed to have more outliers like you in the scientific community!!

    • Ha…very kind. Glad you’re keeping you eye on the important metrics: your goals (vs. those of others).

    • Jean

      There is an eye-opening documentary (available through Netflix) called “Food Matters.” Also, the book “Dead Doctors Don’t Lie” is almost shocking, especially Chapter 15, The Age Beaters. Other research and studies are pointing to the lack of essential nutrients (especially trace minerals) as the cause of most poor health concerns. . Once again, read Chapter 15 referenced above and then read whatever else you can find on micronutrients and how there came to be a depletion of them in our food supply. “Healthy,” “Organic,” (maybe, maybe not), “Low Calorie,” “Low Sodium,” “Dietary Fiber,” — BALONEY ! For example, what is a more basic need than plain salt? Read the label on table salt; why is dextrose (sugar) added to salt??? Much of our food supply is no longer supporting our bodies.

  • Mike


    Could you tell me if you had any deficiencies before, during or after this experiment?
    Specifically, Vitamin D and B12.

    I am finding some research indicating Vitamin D deficiency could have a role to play in insulin resistance.


    • Yes, both of the ones you mention, though neither were “severe.” I do supplement B12 and vit D (D3), but only started a year ago, long after IR improved.

    • Kevin

      Mr Attia,

      Would you say that the light B12 deficiency was due to the nutritional ketosis diet? I thought that B12 came in ample supply when eating meat and eggs. I understand why vitamin D is more of a problem because of limited milk intake but I am confused about B12. Is there a link between low carb/high fat and B12 that I am unaware of?

      Thank you,


  • Peter,

    My glucose hovers around 119 while my A1c was just measured at 5.5. I follow a very low carb high protein diet. During the week I usually eat once a day at dinner with the family. Since 2011 I have lost 55 pounds and have never before been this strong…I am 57.

    My only concern is the level of glucose. Is one possible explanation the fact that my liver is producing glucose from the protein and that I need to adjust the ratio of fat to protein by increasing the fat % of total calories? Having said that my one remaining vice is my love of several drinks that contain splenda. Do you know of any reputable studies that show consuming splenda drives up glucose?

    Is that level of glucose generally considered harmful? All my other markers seem to be in order. I just had a Male Panel Blood test purchased from Life Extension that is interesting reading.

    Thank you for your efforts in this field. Between you and Gary Taubes I have my life back…I was seriously feeling old when I started this journey back in 2011. Not anymore.

    • Great to hear about your transformation, Pierre. To answer your last question, it’s definitely possible that non-nutritive sweeteners can alter glucose and/or insulin, but it’s poorly understood. I wrote a post on this a long time ago you should be able to find. Always interpret home (POC) glucose meters with a grain of salt. They are usually +/- 10 mg/dL, often skewed towards being too high.

  • Calin Culianu

    When is that TEDMED talk you did a couple of months ago going to be published online?

    • Next week some time on the TED website. Not sure exactly which day, but should be up no later than the 28th of June.

  • Birgit Sun

    What an outstanding talk, and it does not bother me to hear the stuff again I already read on the blog. I’m understanding it better every time,meaning I can pass it on to others. 🙂
    My 16-year-old daughter, who is a highschool swimmer (no events over 500 free) was listening with interest. Are there performance benefits for this type of swimming of being in ketosis for someone borderline pre-diabetic (HA1c 5.7)? How to find a coach that won’t advocate carb-loading? Would it be better to include longer workouts or lowering carbs to increase ketone levels?

    Hope you will buy a second fridge, at least a dorm room size. 😉


    • Birgit, glad you enjoyed. If your daughter has a Hb A1C of 5.7 I would check that she’s not a carrier for thalessemia (a simple blood test called a CBC can confirm this). If she is, then A1C is elevated as an artifact and doesn’t represent the risk is does normally. I’ll try to address your broader question in a separate post, but the short answer is that ketosis may not be necessary, given her age and focus on sprinting. It’s more about cleaning up the quality of the carbs she consumes and getting the timing right. Hope to cover in the next few months.

    • Birgit Sun

      Peter, thanks so much for the feedback, it helps a lot. My daughter’s hemoglobin levels were tested and found normal so I assume that means no thalessemia. She is cutting out sugar, grains, legumes already and keeping carbs under 80-100 grams/day, a little higher in fruit and rare gluten-free treats. We are retesting HA1c every 3 months with a low-carb/paleo-friendly physician. Interestingly enough body composition is perfect, between 10-15% body fat. I suspect there is an epi-genetic component to her insulin resistance as I was a sugar addict for many years.
      Looking forward to more info on this from you in the future. 🙂

      • Actually, Hct or Hb can’t always tell. The diagnosis lies in the MCV and RBC, but I’ll assume her doctor has checked the MCV and RBC numbers.

    • Birgit Sun

      Thanks for the follow-up. MCV was 81, RBC 4.99, Hct 40.6 and Hb 13.9
      My daughter seems to be too young, too much of an athlete and on too healthy a diet to be pre-diabetic, but if that’s what it is I’m sure glad we are catching it early. I had been weight-loss resistant, had cancer several times (Hodgkin’s, melanoma, breast cancer), thyroid issues and memory problems and was unable to improve my cardio until I read your blog and switched to a ketogenic diet. After about 6 months I found out that I had been pre-diabetic as well. I am hoping to spare my daughter the terrible medical history I had. Thanks again for all you do!
      I’m spreading the word about it every chance I get.

      • Yup, you’re right. No thal. Glad you’re helping your daughter be proactive.

    • HA1c

      Another opinion about the A1c for paleo people:

  • Christopher Kelly

    Fantastic presentation, thank you for making it public.

    Am I right in thinking that you can only replenish depleted muscle glycogen by consuming carbohydrate?

    • That is definitely the best way to do so. Less efficient ways involve protein and glycerol (from fatty acid breakdown). At some point, in a follow up to this post, I’ll explain how I calculate my carb need for ideal replacement without getting kicked out of ketosis. Much more art than science.

  • Jason

    Thank you for posting this talk. It is a good primer I can share with others who ask me about ketosis.

    It was also nice to see your “average” ketones levels between between 1 and 2. After all the discussions I see on the Internet about people saying they are between 4 and 5 all the time I was having “ketone envy” 🙂 I am generally between 1 and 1.5 but higher during/after extended endurance sessions.

    In the interest of adding another experimental data points in “how long can I go without food” angle my latest attempt was a 9 hour mountain run with just electrolytes and water and I was still not really hungry until the next day. It really is amazing to push some of this stuff sometimes..

    I appreciate the attempt at not seeming like you are pushing ketosis on people I would be interested if someday you could discuss in what cases you have seen where ketosis is NOT ideal for someone. Perhaps some sort of metabolic damage or (epi)genetics that make it not ideal ? It seems like such a ‘base line’ functioning of the body.

    Thanks again.

    • Jason

      As a follow-up question, do you know if there is any data that describes the rate of glucose generation from the usage of fat (or whatever metabolic leftovers) ?

      I am curious, given a certain RQ for someone, we are using a set amount of glucose so I am wondering if there is a ‘threshold’ for RQ where you are outpacing your body’s ability to create glucose from protein/BCAA/fats that would determine when an exogenous source of glucose is required. For example if my RQ rose to .86 that would mean I need to take in glucose to supplement the body’s creation of glucose.

      Of course we would not know this while exercising but maybe it could be tied back to heart rate. If my heart rate is over 140+ then I need exogenous glucose.

      Thanks again 🙂

      • I don’t know the exact answer to your first question, but the answer is ‘absolutely’ to your second question.

    • Very interesting on your attempt. Love the concept of ketone envy… I don’t know how to tell a priori who won’t do well on ketogenic diet, but there are folks who don’t. Trouble is I’m only able to figure it out after a few months. Small investment in time, though, given our lifespan.

  • Gasper

    Great presentation! Did you ever check if BCAA use ( my be without exercise) change your ketons level? Or what do you think abot that?

    • No, but impact would be minimal, given doses (re: very low).

  • steve

    Excellent talk/presentation. While you experimented with one meal per day, have you thought about an experiment with two meals per day with total carbs of 100-150Grams ? It might be interesting to see if the biomarkers are any different, and how you might feel exercise and otherwise? Ketosis obviously got our early ancestors through famine; and has short term benefits, but it is unclear to me that a state of ongoing nutritional ketosis for 30 or more years is the way to go.
    Unfortunately, successful people and seekers of truth will have critics. Pay them no attention as there are many more out there who are benefiting from your endeavors as they try to maximize their individual health in light of their goals. Thanks for the great effort.

    • Have not done exactly what you described. Appreciate the encouragement.

  • Bob

    Do you think that one could, over time, become bile-resistant from processing too much fat in the same manner that one can become insulin-resistant from processing too much sugar? Or are there pancreatic beta cell equivalents in the liver or gall bladder that might burn out from frequent, heavy production of bile? I’m just wondering if there might be a prolonged lipid-usage syndrome we’re presently not aware of that might show up on the radar after years in ketosis much like metabolic syndrome can rear its ugly head after years (or decades) of heavy carb usage.

    • Completely different mechanism. Never say never, but the association between eating fat and GB disease is, in my opinion, an association, not a cause.

  • Ann

    My husband and I attended this talk at IHMC. BRAVO! We are runners in our mid 50s and, although we are not Elite in stature, we have goals that are meaningful and approriate for us individually. We both left that evening with grateful hearts and knowing we were meant to hear this message. We started with giving up sugar as our single focus. I don’t have any cravings for it and energy is off the charts. I have gone ” GUless ” and my runs feel better. I am almost giddy with excitement for living healthier as we age. We have incorporated other points of your discussion but it all started with removing sugar from the diet. Thank you for the work you do.

    • Fantastic to hear, Ann. Best of luck to you both as you begin your own journey in self quantification and experimentation.

  • Nathan

    Hello Peter,

    I am very interested in the mental acuity aspect of nutritional ketosis. Do you know of any research in this area that might explain the correlation between high ketone levels and increased cognitive function or of any methods to objectively test if this correlation/ causal relationship is real or imagined?


    • It’s a bit a leap, to my reading of the literature, from two other clinical and scientific observations: 1) ketones, by bypassing PDH in neurons, appear to improve cognitive impairment in AD (well established in mice; less so in humans to date); 2) normalization of blood glucose and insulin levels consistently appears to improve concentration, focus, etc. in human subjects.

      There are ongoing efforts to explore this further to see if such a link can be established. More questions than answers at this point (e.g., is it the effect of #1 or #2 that plays a bigger role?).

    • I wrote my master’s thesis on Alzheimer’s Disease as Type 3 diabetes and the potential therapeutic role for low-carb & ketogenic diets. There’s most definitely something to the link between ketones and cognitive function. Look on PubMed for papers by RL Veech: http://www.ncbi.nlm.nih.gov/pubmed?term=Veech%20RL%5BAuthor%5D&cauthor=true&cauthor_uid=14769489 or ST Henderson: http://www.ncbi.nlm.nih.gov/pubmed?term=Henderson%20ST%5BAuthor%5D&cauthor=true&cauthor_uid=18625458

      Mostly it has to do with similar mechanisms in the brain as in the periphery — in a T2 diabetic, the peripheral muscles & organs lose their ability to metabolize glucose effectively. The same can happen in the brain (plus oxidative stress, cholesterol transport issues, and a host of other factors, but the inability to metabolize glucose well is the biggie) — and by providing ketones, we give those struggling neurons an alternative fuel supply. In the same way that obese, chronically inflamed & in pain diabetics often experience high energy levels seemingly out of nowhere when they become ketogenic (because their body finally has access to fuels it can use properly), this happens in the brain — providing ketones to those brain cells gives them that energy boost they were no longer able to get from glucose.

      Henderson & others have conducted RCTs in humans using exogenous ketones as well as low-carb diets, but overall, human studies are in pathetically short supply. (Partly because the establishment is still somewhat terrified of the implications of putting subjects on very high fat diets, especially saturated fat. And I suspect the exogenous ketones [usually administered as MCT drinks] are not as effective as a very low-carb diet with a keto supplement as merely an adjunct, so there might be reluctance on the part of researchers [or their funders!] to pay for further research when the outcomes are not as earth-shattering as they’d hoped. Again, this is likely due to people being put on MCT drinks without any guidance regarding cutting way back on CHO intake.)

      This stuff is fascinating. And thank goodness, or my research would have been paaaaaainful.

    • Sorry — the links in my reply are not correct! Disregard them…but the authors’ names are the right ones, so you can just do a search for those.

  • Ben

    Although worthy, genuinely bioavailable, ketone bodies are not commercially available as of yet, is it true that MCT oil (and coconut oil to a lesser degree) can assist in stimulating production of ketones? What is MCT oil’s value, if any, in moving, or assisting towards a keto-adapted state and getting ketones fuelling the brain ASAP and the rest of the body? (great talk by the way, thanks!)

    • Yes, MCT oil does stimulate the synthesis of B-OHB to varying degrees in people. Its use can be limited, in many, due to GI distress.

  • Good stuff. Peter, I’m interested, based on my understanding that RQ tends to *increase* at altitude, whether you can point me in the direction the ketosis/altitude studies you mentioned in this talk.

    • Ben, what I was referring to was the studies (mostly by Veech, et al) that demonstrate reduced oxygen requirement for power output when the mitochondria use B-OHB and AcAC in combination with glucose and FFA (vs. glucose + FFA alone, as in a “normal” state). This is the “Delta G arbitrage” I wrote about in the earlier posts on ketosis. The increase typically seen in RQ at altitude is, I believe, transient as the respiratory system hyperventilates to correct the perceived hypoxia (as ventilation goes up, VCO2 goes up, RQ goes up).

      What I noticed, contrasting two intense training experiences I had in Colorado (one in early 2011, before ketosis; the other in mid 2012, a year into ketosis) was a significant reduction in “air hunger” at altitude (both times in Colorado). Looking at my telemetry data, I noticed that I seemed to have less heart rate elevation (and presumably less O2 requirement) for similar demands while in ketosis.

    • Interesting. You should check out 1st paragraph here for summary of my thoughts: http://www.jappl.org/content/88/1/246.full

  • Olivia

    There seem to be a significant number of people who experience elevated fasting glucose levels on a low carb diet. (This was alluded to by an earlier commenter in this thread.) The question is, why, as one would expect the opposite to occur. In my own case, I have definitely lost weight on the diet (I am now very lean) but my fasting glucose has gone from the 90s pre-diet to 109. Should I infer from this that, weight loss notwithstanding, the diet is not having the desired effect of insulin inhibition?

    Thank you so much for a fantastic blog!!

    • Olivia, yes, I have seen in this a small, but non-trivial subset of folks. At least in the cases I have seen, Hb A1C goes down, as does fasting insulin, as does OGTT response and TG, but nevertheless, fasting glucose is slightly higher. I have a few ideas why this might be happening (Mark Sisson wrote out this on MDA once, I think), but the bigger question is, is a bad thing? I do not believe it to be so.

    • LeonRover

      Hi Peter,

      In your reply to Olivia you write – ” but nevertheless, fasting glucose is slightly higher”.

      I would be grateful if you able to put a figure on the description – ‘slightly’.

      Might it be about 0.5 mmol (9mg) , 1 mmol (18mg) or . . . .

      ( I am a nerd for data – quantification, I guess.)

      BTW, I enjoyed the presentation. Thanks for releasing.

      • Probably between 0.25 and 0.5 or maybe up to 1 mM.

    • JR

      Petro Dobromylskyj at Hyperlipid, AKA http://high-fat-nutrition.blogspot.com/ has a series of detailed, studious articles about this phenomenon which he refers to as Physiological Insulin Resistance (I think Mark Sisson discusses it as Peripheral Insulin Resistance). The takeaway I got was that it’s a good sign; that your body is raising GH and mobilizing fatty acids as a fuel which causes the muscles to protectively refuse some glucose because they are being fueled by the cleaner burning FAs (proportionally less NADH going into the leakier complex I on the electron transport chain) and also the body is hanging onto some glucose for the brain’s use in the absence of dietary glucose. I think his experience has been even a bit higher fasting blood sugar (120 I think) but it didn’t deter him from continuing his very low carb intake.

  • Birgit Sun

    In light of the AMA decision to declare obesity a disease your publication of his talk was so very timely. Bariatric physicians may be able to give this the right interpretation in the sense that primary-care providers need to refer to specialists when they are unable, as most are, to help cure their patients of obesity. I hope that your talk will spread far enough on youtube that patients will educate their physicians, if necessary by showing them results, before our health care system collapses.
    My one question, concerning your point that a ketogenic diet does not work for everyone. What is your estimated guess for what percent of the obese/overweight population a well-formulated low-carb diet does work? Also, are there any medical conditions that you know of where trying it could be harmful?
    Is there any reason to not shout the message from the rooftops via social media?

    • I just don’t know. I don’t think we have enough data to answer that with certainty.

  • Matthew

    When I look up Weir Coefficients on the web, it looks like everyone just uses 3.94 and 1.11. Could you tell me how you calculate different coefficients? Thanks.

    • SUPER COMPLICATED! It requires knowing the exact heats of combustion for ever single food you consume and solving a series of 8 equations with slightly more unknowns (and making an assumption).

  • Mike Kramer

    Until I read this post, I only knew one thing about IHMC: they make and distribute for free (donations welcome) an application called CmapTools, of which I am an enthusiastic user.

    CmapTools is a computer application for creating Concept Maps. Few people have heard of concept maps, but more might be familiar with graphic organizers or mind maps, which are related to, yet different from, concept maps. Perhaps the best way to learn what a concept map is, is to look at this concept map explaining concept maps, created by IHMC:


    Why would anyone care about concept maps? Because if you have something you want to express, one of the best ways to make sure that your thinking is rigorous and clear is to put it into a concept map. And, if you would like, you can use CmapTools to create a Powerpoint-like presentation with your concept map.

    I have found that concept maps are also excellent tools for helping me to learn new information. If I am confused about a subject, I will create a concept map on it. Not too long ago, a study was published which included concept maps, and it received a fair amount of publicity:


    Some readers have misinterpreted the study to be saying that concept maps perform worse than other methods of learning. However, that conclusion is not supported by the evidence. What that study (and the entire research program of Roediger and Karpicke) demonstrates is that if you want to learn something, taking notes or drawing a concept map from an open book is not a very good method. A better method is to read the material, close the book, and then take notes or draw a concept map. Then open the book, review the material, close the book, and revise your notes or concept map. The key is not to work from an open book, but to close the book and work from memory.

    This is called “retrieval practice,” and I have only been doing for the past three weeks. As the researchers demonstrate it is counterintuitive and seems as if it would be less effective than working directly from an open book. But it’s not.

    In the study, concept mapping with an open book was pitted against retrieval practice with a closed book. Retrieval practice won. But I believe that one of the authors, Karpicke, was planning on doing another study in which subjects create concept maps after closing their books. Concept maps are helpful, but, like anything else, they work better when they are created after the book is closed.

    I know that this might seem like a digression upon a digression. But I believe that anyone who follows Peter’s blog has a penchant for learning new knowledge domains and a willingness to test counterintuitive practices.

    • Mike, I am a huge fan of these and Ken Ford (CEO of IHMC) have discussed how useful this tool could be for mapping out what is understood about nutrition science. We have plans for discussing if NuSI can use these tools to better communicate eventually.

  • Pierre Legrand


    Any experience or opinion regarding this product? I have no stake in it.

    Blue Ice Royal Butter Oil / Fermented Cod Liver Oil Blend

    • No idea.

    • lloyd

      Butter Oil plus ketogenic diet reduced my annual time in the dental hygenist chair by seventy five percent, within one year of use. Well worth the experiment at over $100/lb.

  • daniel

    “BTW – you won’t catch me complaining when I have a friendly audience. It’s really refreshing once in a while. I’m pretty tired of getting yelled at and told I’m an idiot.”

    Peter, i discovered your blog after reading similar ones for a year ( i reached here via Tom Naughton’s one ). People like you literally saved my life ( i had depression ), and i want to just thank you for all you’ve done. I hope my recognition at least mitigates the effect of the hordes of idiots you had the displeasure talking to.

    From Brazil, with admiration.

  • Greg

    Great speech. Do you ever think there’s a time where you could do weight training in the metabolic chamber? My major form of exercise is weight training, and I have done it in and out of ketosis. It might be close to the plyo work you did, but I’d love to compare and contrast the data.

    • They’re not really big enough for “serious” stuff, but the pushups and plyos probably give some indication of the energy requirements.

  • Frank

    Thanks Peter! Great presentation that I could actually understand and take some pointers from.

    I just turned 48 today ( yeah birthday ! ) and have three of the markers for metabolic syndrome. My current doctor has me on crestor and just tells me to exercise more. I am now super excited to read more on your blog and see if I can improve my life! Would really like to get away from popping a pill everyday.

    One question – you spoke of the genetic factor in your presentation. What is the best way to determine if I’m a good gene or bad gene person?

    Thanks for your help and keep on testing the limits!

    • Factors, really. There are several, but rarely are they single genes (apoE being a rare exception).

  • Martin

    Peter, it’s a very interesting set of experiments and a great talk. I myself have followed Phinney & Volek’s prescription for nutritional ketosis for a year now and my results don’t seem to be that different from yours except I have not quanitifed them precisely as you have.

    I’d have two questions:

    1. You mention around minute 52 that your resting energy expenditure is consistently higher than predicted. Do you think it has more to do with the keto-adaptation or the exercise regime; would you consider it an empirical proof for the so called “atkins edge”?

    2. I have recently done some reading of Jack Kruse. What he is saying/speculating is that cold exposure enhances the positive effects of ketosis both for health and performance. Do you have any thoughts on that?

    Thanks, Martin

    • 1. GREAT question, and the real answer (based on unpublished data I’ve seen) may be both. In other words, it might be that lower RQ + exercise increased TEE more than either one by more than the effect of addition (i.e., true accretion).
      2. No idea.

    • Hemming

      Hi Martin,

      1. Jack also mentions this in his blogs. His view is that when your cirdacian/inner clock is working optimally calories are not an issue as you’re metabolism will simply increase when you increase calories and you generate more heat. That’s also why he says one of the health markers he look for is how good you are at tolerating cold. So Peter would be able to generate heat from the extra calories instead of storing them as fat. I think it goes far beyond calories and it’s about homeostasis in the really big picture. Diet is important (Jack talks about electron density of food) – but there is more to it.

      2. In my own personal experience I think that CT is an awesome tool for therapeutic and overall health benefits. As I’m not really exercising at the moment due to an eating disorder I can’t comment on that. My mood is obviously affected by the eating disorder but I’ve found CT to be a great tool for helping with that too. CT is also a good way to exercise because the body has to respond to the cold. What has surprised is how quickly I’ve adapted to cold temperatures. You should go to Jack’s forum and read the thread ‘Fasted State Training Adaptions’ – there are a lot of observations and clearly no size fits all.

      Best regards,


    • Martin

      Hi Hemming,

      thanks for the comments on CT! I have no doubts, based on my own experience, that ketosis offers advantages for both health experience. Now I am intrigued by CT as the next step. One problem with Jack’s writing, though, is that it seems a bit… speculative.

      You write that you use CT and see its benefits, I would 2 questions on this:

      1. do you do the extreme version with ice baths or limit the cold exposure to e.g. cold showers, less clothing in winter, etc?
      2. how long did you do it before seeing the actual benefits that Jack talks about?

      As for the training in a fasted state, I already do it, both endurance runs and high intensity climbing/bouldering and it works for me great.

      Thanks, Tomasz

    • lloyd

      I’ve been doing Jack’s CT protocal for 15 months now. It’s every thing the guy has”speculated” on. Its uncanny how “excercise-like” the experience is. Except it lowers cortisol and injuries ,the more you do it. The effect of CT was almost immediate.,(sexual function and strength in the gym).and increased over time.

  • Thomas

    Have you ever analyzed the calorific content of your excrements? In articles about people eating varying amounts of food and authors hypothesizing about the reasons for weight gain or lack thereof, the assumption usually seems to be that the calories leaving the body via excrements is zero or at least constant, regardless of food intake. To me this appears counter-intuitive. I would really appreciate if you could point me to a paper that deals with this question. And many thanks for the very interesting information you have already shared with us.

    • I have not done stool calorimetery, but it’s doable. I have done 24 hour urine collections with quantification of nitrogen and ketones. Neither account for much loss. Total ketone lost in 24 hours is less than 1 gm when I tested.

    • PhilT

      http://ajcn.nutrition.org/content/96/2/296/T2.expansion.html has some stool calorific / composition data relevant to nut inclusion in a diet, it does vary.

  • Jay Moore

    Thank you for all the time and effort to share your story and research with me . I really enjoyed the the video – it helped clarify, in my own mind, some of the points you have been making in your blog. In reading your blog replies, I was very disappointed to read that you had received negative feedback about mentioning specific supplements.
    I truly appreciate you giving specific recommendations and experiences you have had with supplements and hope that you will at least consider mentioning different products in the future. With the 1000’s available, it is almost impossible to discern between the “good, the bad and the ugly”. I can make my own decision, if I want to buy a product or not:, but, your specific input is very much appreciated and desired. One of your product recommendations has made a tremendous difference in my performance and I would have never found it, tried it, or trusted, it without your blog post.
    I can only imagine the frustration of providing this blog and then being criticized for providing specific name brand products that help; but, at least for me, I really want those recommendations and opinions to start my own research from.
    Please keep up the great work – it is changing lives.

    • Thanks so much, Jay. I do wish there was a way to openly discuss this, as I am constantly tweaking my supplements, but maybe one day I’ll write a dedicated post to address this with a 50 disclaimers stating that I don’t sell them or profit from their sale or anything else. I’m 100% for disclosure, and really believe in it, so I was very irked with a bit of feedback I got for writing about super starch when I disclosed in that video that I had no conflict of interest.

    • Liz

      Hear Hear!!

    • Andy Benkert

      I agree wholeheartedly and hope you will, in the future, continue to mention products you believe in and use. I am capable of doing my own due diligence, but having some recommendations from someone with your background makes the process quicker and easier.

  • Colleen

    I really enjoyed your talk!

  • Mark

    Hi Peter,

    I was just at the annual AMA conference. I got to sit in on the reference committee and hear the argument for/against classifying obesity as a disease. I had just watched this the night before. In general, I don’t like ad hominem arguments, but I could not take many of these (overweight) doctors seriously. Moreover, going through medical school, I have had really no education on nutrition. In fact, talking to my student colleagues over dinner that night, none of us know much about nutrition, considered a “soft science”, and instead are just making stuff up based on other physiology.

    All this to say one, I lost the debate and the AMA now considers obesity a disease, and two, please keep up the good work (with clear, cited explanations) because honestly, you are my only education on the topic.

    • Personally, I have mixed feelings about this decision, which may eventually warrant an entire blog post. I’m honored that you find the blog a helpful component of your CME (effectively).

  • Jake Jaglarski

    Hey Peter, loved the presentation. I just came here with a few direct questions. I’ve been really digging into everything ketosis for awhile now (should probably stop and do my studies, lol), and I’ve found your blog to be on of the most informative sources of information on ketosis/ketogenesis. Nonetheless, I have some questions:

    (1) Protein and ketosis: You have stated, as have others (Phinney/Volek/Taubes/Ron Rosedale/etc.) that protein can inhibit ketogenesis due to insulin spikes and gluconeogenesis. I have seen some evidence that this may not be true: http://www.lucastafur.com/search/label/high%20protein and http://www.ketotic.org/2013/02/protein-ketogenesis-and-glucose.html (this is actually the final post in a series of posts on protein and ketosis). Do you think that after a period of being in ketosis, one can tolerate more protein, or maybe if one is also fasting and/or resistance training?

    (2) Muscle Building and ketosis: in brief, I feel as though I should be heavier than I currently am (after a period of yo-yo dieting and vegetarianism until I’ve finally found traditional styles of eating). I’m starting to believe that ketosis may be beneficial in terms of longevity, but as many have seen it is tough to do highly intense activities. You are one that is on the fringe of modern science as far as I can tell, though there are others: http://jackkruse.com/forum/showthread.php?297-Fasted-State-Training-Adaptations; do you believe it is possible to stimulate muscle growth in an absence of carbs, rather than doing a cyclical ketogenic diet that I’ve been doing (Bulletproof Diet/Lyle McDonald)?

    (3) Ketosis + Aminos/supplements: Paul Jaminet (of Perfect Health Diet) shows research on ketogenic diets supplemented with amino acids, namely leucine and lysine (and I believe some others to prevent *possible* toxicity) to increase the amount of ketones produced; what do you think of this? Could an individual get away with more carbs and sustain glycogen a little more if they were supplementing with these and maybe MCTs? Lastly, if you had only one supplement, piece of tech for quantification and tracking, or ‘supplemental food’ (Ben.G eating sweetbreads in his experiment) for an individual looking to push the limits athletically with ketosis, what would it be?

    Thanks in advance for any possible insights – sorry this was kind of lengthy. Again, I love the blog and I reference you a lot on various forums I browse, you can truly synthesize and lay out information in a remarkable way that allows people who haven’t yet gotten/don’t have your knowledge to understand.

    • Mostly addressed in the posts and comments about ketosis (5 posts in total, plus their respective comments).

  • Pingback: the intersection of food and performance | Primal Goalkeeping || 'Keeper Central()

  • Graham

    Wow,wow,and wow,
    Have been following your blog for a few months now. Great presentation, which reinforced much of the info in the blog posts. I have been tweaking my nutrition based on much of your info for an upcoming Ironman distance triathlon I am doing in July. I am 51 and hope to go sub 8:52 which I think would be a new world best time, un officially for an over 50 athlete!. I will be using Super Starch for carbs on the bike! Over here in the Uk, it reflects the USA in it’s nutritional habits, a good friend of mine is a food scientist and really big on the negative role sugar is playing on the health of the Nation, often giving talks to clubs, such as the swimming club where his daughter swims. He works with producers of sugar filled products. The problem is chicken and egg, if they produce products which are low in sugar high in fat they just won’t sell, due too the ignorance of the consumer. Therefore it will be a slow process of education of the masses, which I think what politics is all about!
    Keep up the fantastic work you are doing. We are trying to do what we can over here as well!

    • Wow, Graham, that would be remarkable. At the risk of stating the obvious, just be sure to train extensively with whatever nutrition plan you plan to put into place on race day.

  • Ryan

    Hello Peter. I’m a huge follower of the Eating Academy, and I’ve become very interested in nutrition, cholesterol, etc.

    I understand that you consume coconut oil. I’ve started consuming it regularly (as of 3 days ago), but I notice that it gives me an uncomfortable chest tightness. Is this the sign of a heart problem, or something else?

  • Butch Phelps

    This is a great talk that I wish more people could understand. I lost 105 lbs. 15 years ago and have kept it off by doing what you are explaining.I was up to 315 lbs in 1996. As a therapist, I became equally as interested in the affects my muscles have on my body because the harder I worked out, the more injuries I had. What I found was, as my muscles shortened and hardened from my workouts. the pain I incurred. When dealing with overweight people, I understand, having been one. that when you hurt you are less likely to do anything. That is just a human response. Helping people to unlock their muscles reduces their chronic pain and gives them freedom of movement. My wife is a Registered Dietitian and she would help them with their nutrition. I would love to talk more with you, in detail, of what I have learned from the muscles and how it relates to what you are doing with nutrition. This is very different from what we normally hear.

    • Wow, very exciting story, Butch. Congratulations to you. I’m sure you and your wife are doing great work helping many people.

  • Dan Hackam MD, PhD

    Peter, what is your opinion on going for long stretches between meals, say, a minimum of 6 hours (and doing this consistently)? I have found it really reduces hunger cravings. I no longer need to snack.

    I read this Buddhist wisdom somewhere:

    “Craving is just like a stray cat. If you keep feeding it, of course it’s going to keep coming around to your house. If you stop feeding it, it will eventually give up and go to someone else’s house to bother them for food.”

    To me, this wisdom in a nutshell applies to any sort of craving or desire. The body seems to sense after a while that there is no good information being generated in the craving sensation and either stops generating it, or the brain stops listening to it. I’ve cut off snacking entirely. To a certain point, hunger is just a habit. After that point, it reflects real physiological need. It can be hard to tell the difference, but if you eat three square meals per day, I just do not see any real need to snack.

    I am now quite active, playing squash alternating with days of brisk walking. I am trying to space the meals at 6 hours apart. I have been tempted to ditch the dinner meal entirely (just due to lack of hunger for it), but I have not had the courage to do so.

    Any thoughts on this approach? Am I being extreme? Do you think it would be beneficial to continue this way, health-wise? Thanks so much.

    Dan Hackam

    • I’m not really sure, Dan. You may recall I did a 6 month experiment of one meal per day (sort of an extreme IF). I love it, and I was certainly at my leanest, but today (back in regular ol’ ketosis) I find I’m performing better (though not quite as lean in bf% or quite as light).

    • Dan Hackam MD, PhD

      Peter, thanks for sharing your thoughts. I will look on the website for that experiment. Sounds like you ate like a buddhist monk (except the vegetarian part; they consume only one meal per day, and it’s usually consumed by noon – theravada buddhists, at least). I wonder how it made you feel. I don’t exercise anywhere close to your intensity, but I’d like to look into this.

    • Dan Hackam MD, PhD

      Hmm. Can’t seem to find it – unless it’s under “What I actually eat Part II – IFIK”.

      My guess is that avoiding swings in glucose and insulin is excellent for your long term oncological and neurological health, as well as the “cardiovasculature”. One way to do this would seem to be eating very few meals per day. However, if counter-regulatory hormones start to kick in – cortisol, epinephrine, norepinephrine, glucagon – this might obviate any benefit. Still, there are some natural experiments that suggest that caloric deprivation extends lifespan – e.g. the World War II Dutch famine, concentration camps survivors, and experiments in chimpanzees, mice, etc. I’m going to try to see how far I get with this, without losing too much more weight and compromising my squash game (I’m sitting at just under 130 lbs right now).

    • Dan Hackam MD, PhD

      Never mind. I found what I was looking for. The “IFIK / What am I eating Part II” section revealed the whole story. I am going to keep spacing meals apart as far as possible, and not snack between meals. If I can get to 8 hours between meals, I can easily drop supper. I think it’s possible to thrive on one meal per day (ie 24 hour fasting cycles).

  • MickyG

    Am a big fan of Dr. Attia. Unbelievable level of detail in his data.

    Ever since I listened to Taubes, and read this blog, I have been religiously following a low-carb, high fat diet for a few months, and I thought the past couple of weeks my body finally adapted to this diet. I didn’t lose weight (I had already lost about 25 lbs on a traditional diet – low-fat, and lots of exercise), but I had been maintaining this weight for over 2-3 months. For the past couple of weeks, though, I see an increase in my weight. I have been eating well (perhaps overeating, sometimes). Sometimes I feel I haven’t been eating enough, like the last week. I expected my body to dive into the fat reserves in my body for energy, but that doesn’t seem to be happening.

    Two questions:
    1. I wonder at what point does the body start using the fat reserves in the body, instead of the dietary fat for energy?
    2. Is there such a thing as ‘starvation mode’ — where my body gets the ‘famine’ signal, and starts conserving energy, instead of spending it?

    Many thanks!

    • Complex (but great) questions… very quickly…
      1. I will attempt to describe this in a post I’m working on about “fat flux”
      2. Yes, and it can happen with and without access to seemingly abundant food supply.

  • Kell Brigan

    My reponse to the TED talk that just went public (06/25/13).

    A baby step in the right direction, I guess, but he’s still speaking of fatness as an abnormality. I don’t hear anyone calling thin people abnormal because some of them get osteoperosis and because their cancer mortaility is higher than anyone else’s. Why always this focus on getting rid of the heaviest third of humanity? 80% of fat people do not now and will never have Type II diabetes. 25% of Type II diabetics are thin people. You can’t talk about fatness and diabetes as if they’re somehow interchangeable or inevitably related. I can’t give him a complete F, but this is certainly no higher than a D. The first step toward less deadly medical “care” is to first get rid of the presumption that a third of humanity shouldn’t exist. Weight falls on a bell curve like anything else. I’ve never seen any evidence anywhere that the heaviest third should be wiped from the face of the earth.

    And the questions on the TED blog about “food addiction” and “HFCS,” etc. are absolutely ridiculous. Again, the underlying assumptions need to be examined FIRST. No one anywhere has even proven that fat people eat more or differently than thinner people. The same food intake, same calories counts, result in DIFFERENT BODY WEIGHTS IN DIFFERENT PEOPLE. Before you do anything else, stop assuming fat people eat more than thinner people. Stop assuming fatness is abnormal. No one, anywhere, has proven that either of these assumptions is based on anything other than bigotry.

    • Kelley

      You make some excellent points, Kell, and I’d be interested to read informed opinions about them from the likes of Peter Attia and Gary Taubes. There is no doubt that the number of overweight & obese people has drastically increased over the last 40 years, which sort of “skews” the bell curve, so I honestly believe there IS an “abnormal” health response occurring in that phenomenon. But, historically, heavier people have always existed, many of whom live long and healthy lives. Why should we lump all overweight folks into the “unhealthy” category? Seriously obese people have issues of mobility and joint problems (aside from whatever problems they may or may not have related to metabolic syndrome, heart disease, etc), but to look at every individual who is 25+ pounds overweight and conclude that s/he is unhealthy is simply reductive. There is a huge amount of bigotry involved, no doubt. I have a bachelor’s degree in nutrition from the 1980s (although I never became a registered dietician), but the first time I heard anyone suggest that body weight in and of itself isn’t a predictor of health was in a meeting with an R.D. I went to see her with my husband, who is a very healthy type-1 diabetic, diagnosed at age 4. This was just a routine visit suggested by his doctor for fine-tuning diet and insulin dosage. Hubby has a naturally compact, solid build (built like a power-lifter or a wrestler), so his BMI is borderline “overweight.” I mentioned that fact to the RD, and she said, “Oh, body weight by itself isn’t a good indicator of someone’s overall health.” (She was very thin, for what it’s worth.) That surprised me, so I did some research, and lo and behold was surprised. What seems to be much more important than weight is WHAT people eat (ie, the quality of their diet) and whether or not they get any exercise. Not talking about the so-called morbidly obese here, but rather the “overweight.” This was over ten years ago, and I haven’t continued that line of research. I’d LOVE to see NuSI address the topic!

  • Conan

    Very interesting talk. Galileo must have had some of the same thoughts about the dogma surrounding science in his day. Maybe, these are always the first steps needed for change to take place. I like the way you are doing it. Much more effective than Jack Kruse, who always talks in code Two questions:
    1. Have you experimented with d-ribose and if so does it effect ketosis?
    2. Do you believe in the mesomorph, ectomorph, endomorph categories. Seems I read years ago that we cannot change from these body types we are born into, however, ketosis seems to say it is possible. Maybe hormones are more at play with all this, and ketosis helps rectify our hormones.

    The Best

  • Amanda

    Hi Peter,

    Having read your site and ‘Why we get fat’ (Taubes) – I just have one question.

    If a person is cutting carbohydrates to <25g per day, is in ketosis and losing fat, and also intermittent fasting (I'm having great success with a 16/8 or 18/6 window most days and 23/1 once or twice a week) – what happens in their body if they drink an artificially sweetened zero calorie soft drink during the fasting period?

    I have read that the sweetened drink can spike an insulin reaction despite there being no carbohydrates in the drink. If insulin is floating around but there is no blood sugar for it to play with, is it going to kick us out of ketosis or slow down progress significantly or cause harm to our bodies (similar to a diabetic injecting too much insulin)?

    Keep up the great work!

    • Great questions. Will address in subsequent post(s).

    • Pierre Legrand

      I have read that the sweetened drink can spike an insulin reaction despite there being no carbohydrates in the drink. If insulin is floating around but there is no blood sugar for it to play with, is it going to kick us out of ketosis or slow down progress significantly or cause harm to our bodies (similar to a diabetic injecting too much insulin)

      Since 2011 I have been attempting to follow a ketogenic diet. Having lost 55 pounds I can attest to the success of the diet. My problem has been that I could never, even with a 3 day fast, register more than a .5 on my Precision Ketone meter. About 5 days ago I stopped all consumption of any kind of artificial sweetener. The main one being splenda and last night I registered .6.

      I find that remarkable and hope this information helps others. I have committed to a month of no artificial sweetener to see what happens. After that time period I may reintroduce stevia.

  • Heidi :)

    I watched your talk on ted.com and it brought me to tears. As a person who has struggled with insulin resistance for years, thank-you for putting in to words things I have known but not known how to fix. I have tried drinking shakes, juice fasts, eating vegan, counting points, eating paleo etc., etc. My doctor is always quick to point out that my weight is the problem and I just need to try harder. I have put a ton of effort and research in to finding something that will work to get the weight off and reverse the insulin resistance, to hopefully add both quantity and quality to my life. Your take on this is refreshing and I know in my heart you are correct. I found your blog and watch the above talk. I found it so informative. I love that you geek out with the numbers. I am very hesitant to put my body in ketosis. I have a daughter with type one diabetes and I am sure you are well aware that the number one cause of death in type one diabetic is ketoacidosis. I know ketones are a different story in a type one diabetic who makes little to no insulin. Ketones in our family are not a welcome thing so it will take a huge effort on my part to welcome them in my own body. If in your practice you are ever looking for test subjects, I would be game. It would be much more reassuring for me to be in ketosis under the close supervision of a doctor such as yourself. I am going to spend the next few days pouring over your blog and will discuss this with my doctor before I begin this process. Thank-you for your work in this area, I hope it will make a difference in my life!

    • Heidi, I’m sorry to hear about your struggles and I’m moved by your comments. Remember, nutritional ketosis (which is to fireplace fires what DKA is to house fires) is not “the answer” … it’s just one place on a nutritional spectrum.

  • Elton Wilson

    Great Talk! I sent the video to some of my family members who ask me about my diet, but won’t read the literature I send them. Much more likely to watch a video.

  • colin innis


    • Thanks so much for your kind words, Colin.

  • Ann Baker

    Hi Peter,
    I am currently studying to be a whole health education with the National Institute of Whole Health based in Boston. They teach only evidence based wellness information from a holistic perspective – physical, emotional, nutritional, environmental (internal and external) and spiritual (Candace Pert’s work). They stress that the effects of food on the body depend on each individual’s organ function, metabolic function, on top of the influence of the 5 elements mentioned above. Just wanted this dream team of researchers of yours to be cognizant of that when coming up with recommendations. Also – Our class on Metabolic syndrome was by an endocrinologist, Dr. Diana Schwarzbein who came to your conclusion in your TED talk many years ago – she has successfully treated 1000s of patients in california looking at all factors influencing metabolism including stress, etc. – will definitely be worth your while to check her out. We need more docs like you to admit the failures of the past and move towards honest answers!!
    Best regards – Ann

  • Klemens

    Peter, thanks so much for posting this. You’re saying in your talk that one does not need to eat fat during exercise as one might as well tap their own fat reserves and it would not make a difference. Is there really no difference in tapping the fat reserves than using the fat from food? A short while ago I went for a long bikeride and took three large pieces of cheese with me. Subjectively, they helped me more than if I had not eaten anything (and it was cheese with only traces of carbs). Also you said you like to take nuts on long rides. Don’t you think the fat also helps you besides the carbs in the nuts?

    But maybe you’ll answer that question in the fat flux post?


    • It might, at least from the process of satiation and maybe gut transit time. But I suspect the hunger we experience during prolonged exercise is more due to hypoglycemia than ATP shortage.

  • Samantha

    Thank you for posting this. I have shared it with many friends who have been asking me “But what do you eat before a [mountain bike] race if you’re in ketosis?”

    I went out of ketosis for the last 2 months and I have been very tired all the time, needing afternoon naps, and I got terrible leg cramps after my last speed run. I also have been bonking. I am so sick of carbs, I don’t know why I was eating them. Back to LC in prep for a 24 hr mtb race at the end of July, I hope I am ketoadapted in time!

    Do you have citations for papers on cancer and ketosis? Are there any? Thanks!

    • Yes, many, but much of the work is in mice or cell lines. I will write about this specifically in part III of the ketosis series.

  • Michelle

    Andreas Eenfeldt posted your TEDMED talk – AMAZING!! GO PETER, GO!! Bless you, your family, and your team as you endeavor to help obese and all insulin resistant people. I was crying at the end too.

  • Adam

    Peter, your presentations are amazing and have become my #1 go to for low carb nutrition information. I have been doing a ketogenic diet for 3 months now, and I can honestly say, I haven’t felt this good since my high school years. Thank you for your hard work, keep it up!

    • Great to hear how well you’re feeling. I know what you mean.

    • Micky G

      Absolutely agree. Between Dr. Phinney, Dr. Attia, and Taubes, we have an amazing team that is willing to do what scientists are supposed to do – question everything!

  • Indy M

    Hello Dr. Attia:

    enjoyed that! You speak as well as you write. Many gifts.
    Waiting for the TEDMED video. Let us know when it is out there.

    On a personal note:

    NK for 5 mos completed.
    – Age ~60.
    – Weight 125 before, 123 now. BMI ~18.
    – Fat(15% before, 9.2%now); happy with progress. I do not crave Carbs or Sugar. Salt often.
    – muscle to weight ratio up ~6%. Hoping this would up my chances for a credible attempt at BQ.
    – A1C clinging to 5.3 . Not much progress there. Jimmy Moore had superior results with his A1C.

    Anyway, NK is definitely working for me. The mind seems to be better focussed more often. Practicing musical scales again, after hiatus of ~20 years!


    • Great to hear. Talk is up on the TED and TEDMED sites.

  • Isaac

    Peter, great post again as usual and the TEDMED talk was awesome. I feel somewhat rejuvenated every time you make a post because obviously, as you have identified, this is a journey and more and more things become clear when we have good science happening and excellent/open minds tackling it. It literally get’s exhausting to A) hear the daily constant bombardment of conventional recommendations and B) to try and explain my dietary habits (after finding your site a year ago) to people who really could care less to take the time to look at real available information but think how I eat is crazy. So again thank you for everything you do.

    A couple questions I’ve thought about:
    Can you talk a little bit about the role of timing/dosing of the foods you eat? What would you expect to happen if you could some how perfectly isolate all your grams of fat at (let’s say) and ate that at breakfast, all your protein at lunch, and then 20-30g of carbs at dinner? Would it still be possible to be in ketosis? You may have touched on this in a response to a post comment somewhere but I could not remember.
    Finally, rather then ask what you would recommend for timing/dosing, what do you do personally as a guideline/range for how much of each you prefer to eat with each meal? Does that make the question less awkward to answer :)? If you answer and say it deserves a separate post I will be upset lol, jk. Thanks Peter

  • ken

    Great talk. Great site. It was only when you mentioned that you are sedentary except for your massive exercise load, that it occurred to me that you might be a low NEAT person and if you’re not familiar with NEAT and Levine you should be.

    NEAT is the acronym for NonExercise Activity Thermogenisis.

    James Levine from the Mayo Clinic originated the idea of the treadmill-desk after doing research in which 20 volunteers were calorie controlled while free-living.

    In the book ‘Move a Little, Lose a lot’ by James A Levine MD PhD (Crown, 2009)
    and in Ch 2 “Thin or Fat? The NEAT difference” Levine explains analyzing the data from the research:

    “… a pattern began to appear. It got stronger and stronger until we could barely contain our excitement. It was as though we’d just uncovered the Rosetta Stone to deciphering the confounding obesity code.

    The difference between the obese men and women and their lean peers came down to one thing and one thing alone: NEAT. Specifically, the obese volunteers sat planted like ferns for a full two and a half hours per day longer than the lean volunteers …”

  • Jeremy Tyler

    When you were intermittent fasting was it stopping you from being keto-adapted (as described by Volek and Phinney)? Thanks.

  • nancy

    I think the TED talk is excellent. A better metaphor (in lieu of bruise and coffee table) might be seeing a red light on the dashboard of your car and then covering the light. We all know that the light is a signal or symptom, covering it doesn’t make the problem go away.

  • Tiffany

    Thank you for all the great info here. Do you know if coffee with heavy cream throws people out of ketosis? I am 41 years old, 5’4″ and weigh ~125. Each day I eat around 10 carbs, 55- 60 g of protein, and lots of added fat mostly from heavy cream in my coffee, coconut oil, and bacon grease. Do you think 4- 6oz cups of coffee with cream each day could keep me from being in ketosis? I still have more fat around my waist than I would like but I am too big of a wimp to prick my finger daily.

    • Typically does not, but that may not explain what you’re experiencing. Hopefully my post on fat flux (hope to write before end of summer) will shed some light on this.

  • Carly Seddon

    Hi Peter, I am advising several close family members about reducing their carbs (and also increasing their exercise) to reverse or halt diabetes and obesity symptoms. However, reading about such keto-diets makes me concerned on two counts and wondered if you have any thoughts: is there a problem short-term with regular bowel movements and the gut flora balance generally? Secondly, longer-term does the lack of insoluble fibre and high proportion of meat and fat increase the risk of bowel cancer? There isn’t much I can find in the literature on this issue tho’ some studies touch on it for example: The Effects of Low-Carbohydrate versus Conventional Weight Loss Diets in Severely Obese Adults: One-Year Follow-up of a Randomized Trial Linda Stern, MD et al Ann Intern Med. 2004;140(10):769-777.
    There is no doubt that keto-diets are effective in reversal of many diabetes and obesity markers including reduction of hypertension: A Randomized Trial of a Low-Carbohydrate Diet vs Orlistat Plus a Low-Fat Diet for Weight Loss, William S. Yancy, MD et al Arch Intern Med. 2010;170(2):136-145.
    I have found your Eating Academy fascinating reading and your new venture of NuSI is a valuable contribution to raising awareness for the benefit of evidence-based health eating. Thank you.

    • Carly, believe it or not, the largest prospective trial looking at the role of fiber in the prevention of colorectal cancer found none. It’s quite likely that Dr. Burkitt’s original observation about the correlation between fiber intake and low rates of cancer was confounded by all the other things the people in that section of Africa were not eating. (See my post on red meat for more on this idea.)

    • Carly Seddon

      Thank you Peter.
      Although not labelled as ketogenic diets per se this is the sort of research about the effects of (long-term) adherence to high fat / high meat / low fibre diets which prompted my question:
      * Curr Issues Intest Microbiol. 2000 Sep;1(2):51-8. Protein degradation in the large intestine: relevance to colorectal cancer. Hughes R, Magee EA, Bingham S.
      * IARC Sci Publ. 2001;154:101-11. Biomarkers in colorectal cancer. Owen RW.
      However, for individuals who are ‘merely’ restricting their carbs but not looking to attain a ketogenic state then eating enough insoluble fibre would not be an issue I guess.
      I would be interested in the details of the prospective study you mention as it would be the proverbial cat amongst the pigeons, given the received wisdom currently.
      Meanwhile, eating plenty of garlic (with your steak!) is considered protective. Wishing you well. Carly.

  • Dan Walker

    I find the perspective on insulin resistance that the body may be actually attempting to “protect” itself against a chronic, and/or acute, toxicity of a commonly found physiological compound (in this case blood sugar) very interesting. Is there anything in the literature, or research, current or past, that you are aware of that considers this same perspective in many (or any) of the cell surface receptor mediated pathologies in other conditions such as physical dependencies on opiates, etc? From this perspective it would seem like the resistance, and/or subsequent reduction in cell surface receptors or attenuation of the receptor mediated response could be some form of “vestigial” adaptation that we may have developed in response to something from our ancestral past or perhaps the body is trying to find a solution to a problem it has never before experienced? Would love to see the results from some genomic and epigenetic analysis done in this area. Love all the stuff I am learning here! Thanks so much, and keep up all the great work!


    • I know this will sound strange, but it’s not exactly clear exactly what happens at the cellular level in IR. The latest thinking is that something goes awry post the process of insulin binding the insulin receptor inside the cell via second messengers, etc.

  • Any thoughts on compounds that pass through the cell wall and act as independent GLUT Translocation mediators such as Vanadyl or the newer preparations of non-racemic formulations of Alpha Lipoic Acid? There are probably others, but those are the only 2 I have any knowledge of.

  • Linda Wyatt

    Stumbled across your website today.
    Such interesting parallels!
    I have just completed 13 months of a very low-carb zero-cheating diet, and couldn’t be happier. I have learned a lot in the process.
    Lately, I’ve been doing a lot of what you mention in various posts- experimenting with timing of food with intermittent fasting, eating less meat, less dairy, less in general. I’ve not only lost 90 pounds, but have also eliminated a variety of concerns, including no longer having migraines.
    Thanks for your effort in sharing information with people. SO MUCH of what people are taught simply isn’t true. It’s great to have a reference to share with people who question what I’m doing and why. Fortunately, my doctor is on board with this, and is one of the people who suggested it in the first place. I was very resistant to the idea for a long time, not believing that it made any sense. I’ve since come to a new understanding of many things about nutrition.
    I have no desire to ever go back to the way I ate before. Sometimes, I “miss” some of the foods I used to eat, but not nearly enough to trade.
    One huge difference is that when I go to a grocery store, most of the aisles are full of things I no longer eat. It is a little staggering how much of the available “food” fits in that category. It really makes the point of just how high in carbs most people’s diets are. I didn’t really think about it before.
    I hope to read through much more of your writing, but there’s a lot!

  • Priya

    Dear Peter, At first when I started watching your talk I thought, oh great, another cocky triathlete-type doctor, but after watching the talk in its entirety, I was really struck by your compassion and your unbridled humility, something I rarely see in doctors, let alone fellow human beings. 🙂 I’m writing to you because I’ve hit a wall, as far as my understanding of diabetes goes. Some brief background – I am a 41 year old South Asian woman and everyone (and I really mean everyone) in my family has diabetes (I’m pretty sure it’s the type 2 kind). I myself have been ‘diagnosed’ as pre-diabetic, despite being thin (BMI of 19) and exercising my whole life and being very diet-conscious (moved from low fat in the 80’s to low carb in the 90’s to more of a modified paleo in the 00’s). Despite these efforts, my fasting BG and A1c/fructosamine levels are still in the ‘almost diabetic range’. I finally went to an endo and he made me get a c-peptide test, which were in the very low normal range, so the doc figures I probably fit more of a Type 1 profile. My question for you is this – what if you are not insulin resistant? Then what? I struggle w/the kind of advice I should offer to my family – do we just have some weird South Asian version of the disease that is impervious to dietary change? How can science explain beta cells just conking out and producing less insulin over time? Am I doing the right thing by restricting my diet and ‘saving’ my beta cells from working too hard? Or does it even matter? I currently live in Bangalore, India and as you probably already know, India is virtually ground zero for diabetes – between the movement towards a more sedentary lifestyle and the advent of processed food galore into the marketplace (and zero regulations around food labeling, packaging, etc), this will become THE problem for 1.2 billion people…but I’m not sure how to reconcile recommendations for diet and lifestyle versus genetic factors (ie some South Asian proclivity for developing the disease). Any thoughts you may have would be really appreciated. Good luck w/all you do and thanks for your time and keeping it raw and real. 🙂 Best regards, Priya

    • Priya, if not a cocky triathlete-type surgeon, at the very least a cocky tire-flipping one 🙂 I completely understand that bias, but I thank you for sticking it out past the the first few min. Your case is very interesting, and I can’t really play armchair doc from so far away, though it sounds like your doctor is pursuing the right line of testing. If hyperglyecimia, with or without hyperinsulinemia, is becoming problematic (the latter suggested by your labs), the dietary treatments may be surprisingly similar. You may want to see a book by Dr. Richard Bernstein, if you haven’t already. The situation you describe is actually becoming not too uncommon in people of Asian decent.

    • Dan Walker


      I’m no clinician by any stretch of the imagination but there IS something known as Beta Cell Exhaustion, which is pretty much as you describe where the cells inside the pancreas that normally would produce insulin simply stop in a person diagnosed with insulin resistance. I have no idea how this presents itself clinically in the people that go through it, ie: if the C-peptide level simply drops to below detectable levels. Would be interesting to have known what your C-peptide levels were from previous times then you could know if they were at one time super high and have reduced over time to where they are currently. I was lucky enough to have an internist that ordered a C-peptide when I had a my first high fasting glucose result that showed up on a routine screen and I was already being treated for high blood pressure. So I had classic metabolic disease. Mine was through the roof so it was pretty obvious what was going on.

      Keep your spirits up!!! I really believe that what we eat is going to be the key and with the help of great people like Peter we will come up with all kinds of information that will help us eradicate all the issues surrounding insulin resistance.


  • Kevin Zummo

    Thank you, thank you, thank you. I have been struggling with my weight since I was a teenager with swings of 40 lbs or more. Last November I happen to see you on John Stossel’s show and the unintended consequences of “bad science” resonated with me. At the time I had crept up to 265 lbs and at 5’-10”, I was the largest I have ever been and again knew I would go on a starvation diet with exercise to lose 20 to 30 lbs like I have done many times before.
    Last November (just after Thanksgiving) I started with your web site (and others similar) and have been following a no-sugar/very low carb diet high in fat. I have you to thank that I now weight 208 lbs and feel better than ever. Keep up your great work.
    I would be happy to help you in any way. I too started out in Mechanical Engineering and did my PhD in Systems Engineering. I’m a numbers person and would be happy to help you in your great endeavor.

    Dr. Kevin J. Zummo

    • Kevin, great to hear of your success. The “key,” if such a term makes sense, is keeping the following in mind — slow and steady. The next 30 pounds (or whatever your goal) won’t be nearly as quick as the first ones, but they will come.

  • J. R. Bardwell

    Dr. Attia – over the past few days, I watched both this video and the TEDMED video, as well read through your site. The videos were terrific and thanks for your willingness to share all of this great information, and your openess to discuss in this forum. I’m a first year medical student, cancer survivor and nutritional testing/data addict myself. I have a few questions and will post them as you write on the future topics. As a future doctor, I want to find a specialty where I can practice in this area. Thanks again for the inspiration.

    • J.R., thanks for your feedback. Hopefully you’ll find some helpful info here as you refine your own nutrition.

  • Dear Peter,
    I think your team should really look at the intestinal bacteria complex between obese and thin people. There is evidence starting to show that the suite of bacteria in our guts controls a lot more of our body’s function than previously thought. This has been hinted at for a few years but the following finding seems to indicate that this may be one of the big factors you are looking for.


    The thing that strikes me with these findings is that the additives the food industry uses maybe having an effect on our gut bacteria to cause the obesity rates we are seeing. I don’t think that it is just eating too much that causes this epidemic to move into the deveolping world when they adopt our food. I think that it is the additives in our food changing the gut bacteria to a suite of bacteria that is causing obesity as a side result.

    I urge you to have someone look in this direction.

    Keep up the good work.
    P Pincha-Wagener

    • Pamela, the NuSI scientists will all be looking at the effects on gut biome, so lots of good stuff to be learned!

  • It’s a bit hard to believe anyone would ever call you “idiot”!

    I love your blog posts & talks, even though I only follow about half the science in them. So, you can’t be an idiot – that would reflect very badly on ME.

    I’m getting a bit fan-girly about your blog – need a new post soon!

    Take care, Peter. 🙂

    • Thanks, Davra. I guess it’s ok to be an “idiot” in good company.

  • mg

    peter, when can you eat 100g of carbs and not get out of ketosis? i assume it’s after work-outs, but I am wondering what type of workout leads to a state when the body can utilize carbs particularly effectively w/o impacting ketosis. Also, can you tell you are in this receptive state either by measuring something or feeling certain way, or is it mostly driven off of what the workout was like (i.e. >1h at over 85% max effort or similar)?

    • I’ll write out this in some detail in the future.

  • Oscar Chalupsky

    Hi ii Peter do you know my adviser and friend Prof Tim Noakes?

    • Yes, Tim is a remarkable person. Honor to know him.

  • mg

    Peter, is there a short answer re: the “100g’s”? I suspect it may be related to how i work out and hoping there is a solution to my problem — i’ve been in ~1-4mmol ketosis for >3 months and am generally feeling ok with the exception of exercising where my performance continues to be very impaired. i tend to work out at quite high intensity (>85-90% of my max HR) for 1-1.5 hours (~3x a week if that matters… it’s generally basketball and biking). is ketosis particularly poorly suited for this type of work at above anaerobic treshold? is this when some limited carb-loading and/or carb-refueling may be effective? thx

    • If responses to blog questions are akin to margin space on a piece of paper…think of what Fermat said.

  • Hakim Hakim


    In the early parts of the video you were talking about glycogen and it being stored in the Liver and the in muscles, up to 70 grams and 300-350, respectively. You stated that muscle glycogen generally can’t be used.

    My question in what instances can muscle glycogen be utilized? I’ve heard in other lectures that it can be used when the muscle in question needs to exert effort or energy. To follow up, assuming muscle glycogen can be depleted, is it a beneficial process in regards to oxidizing and burning fat?

    Love your work

    • Sorry, Hakim, I may have glossed over this point…muscle glycogen can’t be used directly by the brain (the muscle lacks an enzyme necessar to release glucose into circulation, so muscle glycogen is used only by muscle, unlike liver glycogen, whic is primarily for export to the body — esp the brain).

    • Hakim Hakim

      Re: Muscle Glycogen.
      I’m thinking more in terms fat spotting. I know the general consensus is you can not pick or choose where to lose fat on your body. But for instance, if you had 30 grams of glycogen in your pectoral (pec) muscles and you were to exercise those muscles strenuously and deplete the glycogen stored in those pec muscles, can the pec muscles then use the stored fat in the surrounding area to continue engaging in the strenuous activity. Or even after the activity is over, can it continue to use the fat in that area until the hypothetical 30g glycogen storage is replenished? Just a thought.

  • mg

    i’m not looking for proof… just the conjecture

    • See, this is what I *love* about the folks who read this blog! Only because you got my dorky reference to FLT… Ok, short answer, I titrate to glycogen replacement by mapping HR to RQ. On the bike I know pretty well the relationship between watts-HR-RQ, so I can calculate my glycogen deficit. On Sunday, for example, I did a lot more than normal, about 5 hours of intense exercise (including a 2.5 hour ride at an average of 200 watts), so I can figure out how much glycogen I needed to replace.

  • Bibi

    Hello Dr Attia,

    I have recently changed my diet and have reduced most carbs, and I have increased the good fats, i.e avocadoes, nuts, full fat yogurt, hard cheeses. Do I have to limit the amount of good fats that I am eating and count calories? I haven’t lost any weight but I think that I am loosing body fat…when can I expect some real results? Is there something that I should be doing differently?


  • Andrew Logan

    Gee Peter,
    This is a terrific talk. Since going on a ketogenic diet, I have lost a lot of weight and generally feel terrific. The best thing for me has been the effect on my mental state – specifically the near-euphoria which kicks in at ketone levels of around 2.2mmol/l. On a scale of 1 to 10 where 1 is a runners high and 10 is being in love/religious epiphany ketosis seems around about a 5! I feel a bit goofy talking about it because it sounds like you are doing drugs but there it is. I think maybe humans are really suppposed to be slim and happy.
    Quite a large number of my acquaintances and extended family members have gone low-carb since seeing the effect on my body mass, and all have easily lost significant amounts of weight, including an overweight 12 year old nephew who has gone from fat to slim, entirely of his own volition – an amazing transformation. Not that many of them seem interested in going into ketosis but your talk will be great resource to point them to.
    I cannot fathom why people get offended by what you are doing – it is just so valuable and interesting. Thanks for all the work you put into this.

    • Andrew, many people who go on well-formulated KD note what you have. For many, it’s the single most important feature.

  • Eileen Apple

    Dr Attia,
    I have watched this and the TED video, they are very informative. I will be watching your progress of your research. I was wondering if your research has anything to do with how much our food has been effected in the last 20 or so years with all of the chemicals that are added and the GMO’s that we have now as well as other chemicals in our bodies the following is why. I had gestational diabetes with both of my pregnancies. I became hypoglycemic after my daughter (24) was born and diabetic after my son (1) was born. My family is also predominantly becomes diabetic in their 40s and are overweight on my mothers side. I was hypoglycemic for over 20 yrs which a lot of people say is unheard of. I was also told I have a magnesium deficiency which I take supplements for. I also take B12 supplements for the energy both are OTC. How many of these are you testing for. I know these are not really looked at a lot because for the most part science thinks they know which one are important like potassium. What if there are other ones that are important but are so slow acting it is just never caught in time? My son will be 2 soon and I went from hypoglycemic to diabetic when I was pregnant, I only gained 5 lbs when I was pregnant. However I have gained 40 lbs since my sons birth. I am now on a low dose of diabetic medication that has just been increased to 2 times a day and slowly my numbers are going up as well as my weight. I am beyond frustrated. I wont eat fruit or drink milk because of the sugar. The only fruits I will have are berries because of their ability to level out sugar and not spike it. I have cut way back on my carbs yet still I keep gaining weight and I am frustrated. If there is something else you find out please let me know I basically have 2 diabetic shakes a day ( extend, is the name, was the best one I could find when I was pregnant) with berries which has 15 grams of protein and 2 carbs per drink, salads and meats, I also crave and eat a lot of cooked onions sometimes 3-4 at a time with mushrooms and at times cheese. if that means anything, no one seems to know. I also crave raw pasta ( I eat dreamfields when this happens which only has 4 digestible carbs.) I also only drink diet caffeine free drinks and water as well as vitamins and my medications. I was not a good eater as a teen, but have been for almost 30 years now. I am not nearly as active because I am raising 3 small children and the oldest is 4. I am constantly on the move but not in a exercising kind of way.

    • Not at this time, though hopefully others are taking a good look at such.

    • Nicky Hansard

      Hi Eileen, I’d recommend a diet consisting solely of vegetables, meat, fish and eggs (don’t count calories just eat as much as you want of those food categories). I would also try an exercise program of 30 minutes a day, 5 days a week, Monday/Wednesday/Friday do some cardio fitness, that by the end of the session you’re exhausted (whether that’s hill sprints or a light jog is up to you but the idea is that it is intense as you can handle) and Tuesday/Thursday lift weights (do full body workouts and heavy weights e.g. Squats, bench press and dead lift with a weight you struggle to lift 8 times x 4).

      That’s all my personal opinion and I’m not Peter. It’s just something I would do for a couple of months to see if some of the issues rectify themselves. All tasty, low allergenic, low processed, low carb, natural foods that pretty much anybody will respond well too with a great strengthening/cardio regime that will hopefully optimise your hormonal profile.

  • Beau

    Really awesome talk Peter! I love your stuff and what you’re doing. Keep it up!!

    Little off topic but I need to know!
    We all love fat, but the one question I have: What about all the trans fat in the dairy? It can’t be good right?

    • Probably a trivial source of TF. BTW – not to be too provocative, but the evidence implicating TF is based on association. TF (in high amounts) tracks with junk food, so it’s not clear which is the problem.

    • Amy B.

      I think you might be referring to CLA — conjugated linoleic acid, a NATURALLY OCCURRING trans fat in the fat & dairy products of ruminant animals. There’s a fair bit of research that these natural trans fatty acids are actually beneficial with regard to cancer and weight control. These are different from the factory-created trans fats that turn liquid vegetable oils into solids under great temperatures & pressure, with nickel catalysts and other such shenanigans.


    • TS


      I don’t mean to speak for Peter here, who is a lot better than me in getting his point across concisely, but I believe what he was getting at is that the data condemning trans fats is (most likely) just observational epidemiology. That is, you look at the diet of a population and you notice that heightened intake of TF is negatively correlated to various markers of health. Now, the problem is there are likely to be an overwhelming amount of confounding factors at play here. Such as the way these people are getting their TF is largely going to be in the form of processed foods that contain plenty of nutritionally-poor ingredients, and likely they have other bad habits such as a lack of physical exercise, etc. To illustrate the potential negative health impact of a TF one would have to do something along the lines of holding a trial with two groups, one as a control and another that consumes X amount more TF as their energy intake for Y amount of time, so the single alternate variable is the intake of TF. (Ideally you’d also want to put forth a theory of exactly what the mechanics of the TF producing a negative health impact might be.) From there you could then look at the difference in whatever biomarkers or mortality between the two groups, and see if there are any outliers within the TF group and further look for a pattern there. And of course even if one type of human-made TF was shown to be bad , it wouldn’t prove that they all were.

      Epidemiological observations are certainly still worthwhile as a source to form a hypothesis from, they just don’t show you cause and effect.

      On the subject of Conjugated Linoleic Acid, one thing that speaks quite positively for it (more so than it just being naturally occurring) is that grass-fed ruminants contain multiple times the amount of CLA than their grain-fed counterparts. If you look at all the other differences between these animals, grass-fed is nutritionally superior in all aspects to the best of my knowledge. Of course this would be just an association, but a pretty strong one in my mind!

  • Guido Vogel

    Hi Peter,

    Great talk. Just finished Wheat Belly by William Davis. He sees (modern) grains as main cause for both obesity and disease. He is not alone in this. Ian Spreadbury also makes this case. Difference is that the pathway to obesity is not via insulin, but acellular carbohydrates promoting an inflammatory microbiota.

    Are you familiar with his work and do you plan to write a piece like “Are grains toxic?”

    • Guido, I know Bill Davis well and like him a lot. Not sure if “Are grains toxic?” is in my blogging future. Seems Bill has already written a book about it. Remember, there can be (and almost assuredly IS) more than one dietary trigger for IR and its related diseases (and for obesity, for that matter).

  • Guido Vogel

    Hi Peter,

    There are two things I find interesting (but maybe you don’t!). You are a firm supporter of the carbs > insulin > fattening hypotehesis.
    1. Why do you think this is superior to “acellular carbohydrates promoting an inflammatory microbiota and causing obesity”(Ian Spreadbury), a “Fat Switch” (Richard Johnson) or the “Food Reward Hypothesis” (Richard Guyenet).
    2. Are all carbs created equal? For example: is wheat worse than rice in terms of weight and health? If not, might this explain (at least partially) that Asian cultures are pretty lean (I also think that their rice intake is overestimated. It is really different, less, from what we consume if we order a meal at the take away).

    • Guido, there is no reason to think these theories are mutually exclusive. Just as Newtonian and quantum physics are not. They just apply under different circumstances. Similarly, I suspect there is great validity to all four of these, and for some people, under some circumstance, one theory appears more dominant. I may simply be biased to spend more time writing about the enzymatic/hormonal regulation of fat tissue than the others, as that was the “one” that most explained my metabolic dysregulation and adiposity.

      To your second question, certainly not.

  • Jacques Drolet

    I work in the area of pesticide regulations. Have you consider the influence of other parameters that could cause metabolism disturbances, such as food additives (those we intentionally put in) and residues (those we would like not to be there but can’t take them out)? And thanks for your passion.

  • Sarah

    I just found your blog! Over the last nine or so years I have essentially been walking to the same conclusions especially about fat and how sugar is more like fat’s evil twin. I have had pancreatitis and live with milk, peanut and shellfish allergies and walk a fine line in the greens department after a bloodclotting “scuffle” I’ve had. (crazy, I know!) Anyway, just wanted to say thanks for doing what you do and giving persons like my self a place to go to get answers. And occasionally pick your brain 🙂

  • Doc,

    How mush different is your program from the Paleo Diet? I see some thing right away like dairy. Where you use heavy cream and they use no dairy from what I can see.

    • Mark-John, I don’t have a program.

    • Sarah

      If you look at this site, they say its not off limits but form is everything. I don’t touch the stuff since I have an allergy but I think eating it in the least refined form and not use it as a possible beverage is most likely ideal.

    • I should have said routine. Sorry. I know there isn’t a formal program. I do know you follow a routine and I am starting it soon based on your drinks and some of your foods.

  • Andrew Logan

    I noticed a couple of questions in previous posts – one on coconut oil, and another two from Amanda and Pierre Le Grande re. effects of artificial sweeteners on ketosis which prompted an “N-1” type experiment today which I found interesting and maybe relevant.In the past, despte a pretty strict, mostly no-carb diet, my ketone levels at best have struggled to get over about 1.2 mmol/l and only rarely over 2. This last week I have started taking coconut oil in my coffee and have found my ketone levels have started to come up.
    This morning I did my experiment on artificial sweeteners. Had my usual breakfast of eggs and bacon, cream and berry smoothie and coffee with cream and coconut oil. Did a 10km run 1 hour after breakfast and started to measure my ketones and blood sugars after the run
    Ketones and sugars immediately after the run were 1.3 and 5.4 respectively ( remeasured 5 minutes later to confirm stability).
    Then held 1 teaspsoon of Stevia in my mouth for 5 minutes and then spat it out and mouth wash.
    5 minutes later – ketone/sugar was 1.8 and 2.4
    15 minutes later- levels were 2.4 and 4.9
    So – no effect from sensation of sweetness in mouth. Rather, ketones continued to rise and glucose levels stable so no effect from sweet taste in mouth.
    1/2 hour later swallowed 1 teaspoon of stevia (really gross)
    5 minutes later levels were 3.11 and 4.7
    30 mintes later – 2.9 and 3.9
    1 hour later ketones had gone to 3.6 ( at this point I was high as a kite – see previous post)
    Over the aftermnoon my ketones dropped to 1.5 with sugar stable at about 4.4
    To test the effect of coconut oil I then drank 1 cup of decaffeinated coffee with cream and 1 tablespoon of coconut oil.
    10 minutes later, my ketone level was back up to 2.6.
    10 minutes after my evening meal (contained a small amount of carb and sugar), ketone was down to 1.3 and blood sugar up to 6.1.
    Conclusions from experiment:
    1. Stevia has no effect on either ketones or blood sugars so presumably no effect on insulin, for me at least
    2. Coconut oil is awesome at getting me into Ketosis with much higher levels than previously achieved with a quite strict LC diet.
    These experiments are quite easy to do with a home-testing meter.

    • Andrew, thanks so much for doing this! I think you know this, but I want to be sure other readers do, also. Some may wonder why B-OHB went from 1.3 to 1.8 to 2.4 mM in a period of 15 min with Stevia in your mouth. I would guess the Stevia had minimal, if any, effect, and the rise was merely your net accumulation of ketones which were still being pumped out of your liver at the same rate they were when you were running, though your body is no longer consuming them.

    • Maryann

      Is there a proper way to add cocunut oil? Is it necessary to use an immersion blender or is it fine to add it in with a spoon? My jar liquified in my cabinet; is it still good? Thanks!

    • Devra Mattes

      MaryAnn: immersion blender is not necessary, been using a spoon for months, also coconut oil does liquefy at room temperature, no worries as it’s a stable saturated fat.

    • Jacob


      -You need to blend your coffee after adding the coconut oil to make a proper emulsion, else it will just float on top because it’s lighter than water.

      -An alternative you could look into is a simple handheld milk frother for this purpose. I have one by the brand “Aerolatte” that works very well and requires practically no clean-up.

      -If you don’t mind to have a small amount of carbs and protein, you could also consider to instead add coconut milk into your coffee. Unlike the coconut oil I assume that it wouldn’t require blending although haven’t tested it myself.

      -If you specifically want your coconut oil to remain solid, store it in the fridge. It’s good either way.

    • Maryann

      Thank you so very much for taking the time to answer my question Devra and Jacob, I really appreciate it! Maryann

  • Lou Guyton

    I viewed your TedMed talk online yesterday and had several ah-hah moments. My daughter who was the most skinny and frail child (we were worried that she would never break 50 pounds in her young life) has had a weight problem now for two years … some of that was medication induced because she is on antidepressants. She also, recently becomes ill after eating (she likes a lot of sugar). We are in the Dallas-Fort Worth area and I’d like to find a physician that ascribes to your hypothesis to have her evaluated. Something about your hypothesis seems to fit here …. and her cravings for starches and sugars magnify no matter what we do. Thank, you Dr Attia for your response. You may message me at my email about Dr.’s in our area.

    • Lou, sorry to hear about your daughter’s struggles. Jimmy Moore’s website has a list of doctors around the country who understand how to work with carb-reduced diets. Hopefully, there will be someone you can find.

  • Andrew Logan

    I just put a tablespoon of coconut oil into the coffee and stir it until melted then add cream and stir it again. I find I drink it pretty quickly because the oil tends to float to the top and looks odd. Taste-wise, I like the taste with the added oil, but like fat and oil anyway. Using a blender seems excessively complicated and the coffee will get cooler while it is being blended. I think something that might work is to warm cream to just above the melting point of coconut oil, add melted oil and blend briefly without causing the cream to thicken. If it worked you could make up enough to last a day or so – ?fat heaven.. an experiment to try!

    • Evan


      1/4 package sweetnlow
      30 ml of Half and half
      large spoonfull of coconut oil


    • Maryann

      Thank you for all of the great ideas!

  • Martin

    Here is an alternative way of eating coconut oil: heat up a spoonful over an oven. I use a big metal spoon. Then just pour it into a yoghurt stirring while doing so. The oil will form small drops in the yoghurt. You could add some berries. It tastes quite good!

    • Martin, that sounds pretty good…

    • Ann Gebhart

      If you like a bit of salty chicken broth while on a ketogenic diet, you might just add some coconut oil to that. It certainly is good added to a cup of the homemade broth that has become a staple around here over the past year and a half.

  • js290

    There may not be one single diet that works for everyone. But, there is a general direction in which optimal diets are pointed: fat burning. Mathematically, variational principles tells us this. For a given set of boundary conditions, you can’t have optimal solutions that are orthogonal. I think it was Ron Rosedale that said health is conferred by the amount of fat one burns.

    Exogenous ketones will probably cause similar unintended consequences as exogenous sources of other things that the body makes, like hormones. Can’t decouple a coupled system. We need to stop trying to out smart nature.

    • Jane

      Good point.

  • grant

    Thank you sir,

    You have a great clear and rational method of discourse that I greatly appreciate.

  • Ayse T

    I have just watched your TED talk and wanted to thank you for voicing this issue. I am a PhD student in epidemiology but also did a graduate work in cancer immunology and public health. I personally believe the current obesity epidemic in the world is associated with the food industry’s practices and it is not the volume of eating, but what goes into that volume and the epigenetic factors effecting the insulin metabolism. Our bodies were not designed to consume all this highly processed food material, simple carbohydrates, food coloring, hormones and corn syrup, stevia, etc. Physiologically none of this makes sense.
    By personal experience, I have seen such incredible changes in people’s body shapes after changing their diet simply from highly processed to vegetables, protein and complex carbohydrates. I am not an overweight person but as I got older, I started gaining weight around my waist area. In 2007, I lived in Spain for 7 months. Within couple of months, the weight around my waist disappeared. After returning back to US, I redistributed my weight again. Then I started paying attention to what I put into my mouth and eliminated simple carbohydrates and all the additives. The result was drastic. When I became a student again, I stopped paying attention to what i was eating and got right back to where I was. As an epidemiologist, I can tell several of Bradford Hill’s suggestions were fulfilled by my own experiment of n=1. 🙂 It is also important to note what kinds of population are mostly devastated by this unhealthy eating practice: youth, students and poor.
    Anyways, instead of putting all our efforts into educating people to eat less and exercise more (which are good goals, but not the right intervention for intended result), we should educate people what to eat and make that affordable by getting the food industry to buy into it. The industry responds to consumer demands, so it is important to make people aware what they are putting into their mouths.

    Thanks again for getting attention to this important topic.

    • Ayse, thanks very much for sharing your experience. I do think a series of well-conducted and well-controlled experiments could elucidate these issues with greater clarity than we have today.

  • Teresa

    Peter….I’m a new fan of yours. I found you on ted talks and have loved what I’ve been learning from you. Thank you. Really… thank you.
    I have a question, I have one kidney (I recently donated one to a stranger) they told me I should never have a high protein diet because of ketosis/ketones is hard on my one remaining kidney. But… I’m skeptical from this advice. I am insulin resistance and when I eat, as I should for being insulin resistance I feel pretty darn good. When I eat, the Food guide Pyramid way….I feel lousy and like I have a hangover in the am. I know this is from the carbs.

    I don’t want to jeapordize my only kidney but what are your thoughts about staying in a nutritional ketosis?

    Thank you

    • Teresa, wow, what an amazing story. Having done a number of kidney transplants (on one particularly difficult stretch in residency, along the attending, we did 13 in 60 hours…zero sleep…very tough, but all the patients did great), I can tell you how much I appreciate your altruism. You’ve saved a life.
      To your question, ketosis is not a high protein diet. In fact, it’s actually a low- to normal-protein diet. In ketosis I consume about 60% of the protein I used to, in my case about 120 gm/day down from an average of about 200 gm/day.

  • Teresa


    You did 13 transplants in 60 hours!!!!! WOW….. I bet that was hard… I am so amazed at doctors stamina when it comes to surgical practices.

    Anyways…..I was so hoping you would give me the advice you did. I am so on the same page with you. You are a breathe of fresh air Peter. I hope more and more people can hear your powerful testimony and amazing scientific studies!

    p.s. I will be allowed to meet my recipient in a couple of weeks. What a cool story – I just can’t believe I’m in the middle of it.

    • Very excited for you to meet your recipient. Some of the most powerful stories I saw in medicine were these ones.

  • Vladimir

    Hi Peter,
    I’ve been low carbing for a year but have only lost 18 lbs. I just measured my fasting glucose and it’s 112 mg/dl.
    which concerns me.I had previously measured it to be 84 using a glucose meter. I read about other people
    experiencing the same issue. My fasting glucose went up to 114 when I started experimenting with intermittent

    Is ketosis making me more insulin resistant? Having fasting glucose this high in the morning can’t be good
    in the long term, right?

    Thanks for having such an informative website.

  • Andrew Logan

    I thought some more about the effects of ketosis on mood and cognition as a result of an experience I had while operating this week. I must sadly confess that I have often had a tendency for my mind to wander while operating (usually microsurgery) which is annoying to say the least. This week I was definitely in ketosis when operating and the difference in my perceived mental state was quite profound – far more focussed and mentally quiet. I would probably not have noticed this doing an activity requiring less attention. Really cool! This was at a ketone level of around 1.2 – no euphoria fortunately. This prompted me to do a google search on “mood & ketosis”. It’s pretty overwhelming – bad science I know – but so many posters who have tried ketosis for weight loss or body building comment on the marked effect in stabilising and improving mood and cognitive function. This somehow got me into the effects of ketosis on mitochondria – this is where it gets really awesome! So many of the potential benefits of ketosis on a whole range of neurological disorders, mitochondrial diseases, cancers and so on seem to be tied to the effects of ketosis on mitochondrial function. A ketotic diet appears to be able to increase mitochondrial numbers and protect mitochondria from damage from such things as reactive oxygen species. This results in increased energy available to cells – this may explain the anti-epileptic effect of ketosis, and possibly the effects on mood and cognition. The best part for me is the potential for preventing or controlling cancer – as a result of my genes I have a 50% chance of developing a particular cancer. I have just started reading Thomas Seyfried’s book “Cancer as a metabolic disease”. He makes a compelling case that almost all types of cancer have the common state of dysfunctional mitochondria that are not able to metabolise glucose using oxidative phosphorylation or metabolise ketones at all. He actually goes further than that and believes most cancers are caused by defective mitochondria and the resulting defective energy metabolism in the cell is what causes the genetic chaos found in cancers. He cites a large amount of experimental data showing that a ketogenic diet which lowers glucose levels significantly and raises ketones can selectively kill off cancer cells which are not able to metabolise ketones and become energy depleted due to the low glucose availability. Most of his work is on aggressive brain tumours but he also cites a lot of work on other cancers. He has found that a ketotic diet (at least in animals) can normalise metabolism in cancer cells and even normalise abnormal gene expression in tumors.
    Go ketosis – what’s not to like. It makes you happy and focussed, helps you lose weight, and boosts your midichlorians!

    • Andrew, I would like to explore the evidence of this more in subsequent posts. There is certainly much N=1 suggestion of improved focus, etc. As far as seizure control, it seems there are several possible mechanisms, which may explain part of the efficacy proposed in Alzheimer’s disease.

    • Andre

      Looks like we are living in interesting times, carbos are being debunked, perhaps most of the cancers are up for debunking next. I started my strict ketogenic diet for that very reason, cancer prevention. Thanks for the book suggestion.

    • Jane

      Andrew and Peter,

      Do you have any insight into how statin drugs fit into this story about ketosis and mitochondria?


  • Anne

    Thanks Peter for sharing this with us, I finally got around to listening to it. It was great to hear the other new stuff and I quite like your four scenarios at the end, it is quite useful for explaining to people that we don’t all need to be in ketosis and why. Interesting to hear you allude to epigenetics and to hear you say the words about cancer that I think we all suspect already. Loved the TedMed talk too. All the best.

    • Thanks, Anne. Glad you enjoyed. It was a bit long, so congrats to you (and others) for making it through.

  • karen

    Does any of the butyrate produced by GI bacteria breaking down prebiotic dietary fiber get absorbed and utilized by us systemically as hydroxybutyrate?

    • I don’t know, but I don’t think so.

    • karen

      This just in! From the discussion section of this study: “… these observations suggest that gut-derived butyrate plays an important role in the pathology of obesity and diabetes.”
      Beneficial metabolic effects of a probiotic via butyrate induced GLP-1 secretion


      Looks like VSL#3 has a wide range of potential health benefits.

      karen lavine rn cde

  • Andre

    Hi Peter, Awesome post. All that testing and analyzing helped me a lot to optimize my diet, you are definitely a hero. I do pretty much 0-carb + 85-100% chocolate most of the time as well, being super liberal on green veggies.
    I didnt get the minerals right initally, now I use just a little bit more salt and supplement potassium, magnesium e calcium, which seems to work excellent.

    Quick questions:
    1) That state of mind you describe – do you have any idea from what level of Beta-Ketones that starts? Whenever I had it and measured I got more than 2.5 mmol, which is pretty high and most probably dont achieve

    2) My wife likes baking and hence once in a while I get to eat a piece of low-carb cake (we use a lot of butter, chia seeds, brown coconut flour, erythritol, coconut oil … all the good stuff) with a lot of unsweetened cream.
    – You say that Carbos and Ketones are inversely related, the impact probably depending on your glycogen stores.
    – In some of your charts we see that ketones go actually up after a meal

    Well, a few days ago I had a piece of thatlow-carb cake with a lot of heavy cream … and my beta-ketones skyrocketed to 2.8 mmol, which was the highest value I ever measured in my blood. I immediately measured urine ketones as well, which were also very high. I dont measure a lot but normally I am around 0.8-1.5 mmol, so I would really like to know where this spike came from. That day I didnt work out as well, so I must have been the cake.
    The only other thing that I ate was a chilli con carne (w/o beans) with a lot of cream as well 5h before that.

    Any theories?

    Some random other feedback
    3) From my own n=1 10 day experiment I can confirm that at least dry red wine does not shut down your ketones. I drank a lot of wine for 10d, but stayed on very low carb and I never had ketones below 0.8 – however I definitely gained weight, even though I worked out quite some.
    Alcohol really seems to work similar to fructose.

    4) I definitely breathe less nowadayw when working out ie running, hence confirming the respiratory quotient.

    • Andre, sounds like you’re well on your way to tweaking your own diet. I don’t know exactly where the effect you describe kicks in, though B-OHB levels north of 2-3 mM are sufficient to provide at least half of the brain’s energy requirements. For some (not all) dairy, especially heavy cream, has a similar effect to MCT, which results in high levels of B-OHB.

  • Michael Hirasuna

    Wonderful talk. Are you planning to use these experimental techniques at NuSI? Your sample size for this experiment was one. How large of a sample size do you think is needed to get consensus?

  • Denise

    Hi! I watched your talk and was very interested in what you have to say. I was diagnosed with type 2 diabetes 2 years ago and I am wondering if the Doctors made the right diagnoses since non of the pills that they give me seem to help. Metformin doesn’t even break down in my stomach…takes about 20 minutes and the pills are in the toilet! My Doctor insists that I keep taking them…to what purpose? lol….my sugars are usually 130 at the lowest and if they go lower then that I don’t feel right…and they want them at 80! I have gallstones also and they won’t take out my gallbladder even though the attacks are worse every time (10 years of fighting to have it removed!) because my sugars are out of control…I’ve seen 5 different doctors with the same results!!! So I’m going to try what you suggest and see if things improve (I’ve lost almost 100 pounds in the last 2 years also)…Do you have any suggestions on the best way to start? and should I involve the doctors that insist on me taking pills that don’t work? Thanks and keep up the good work!!!!

    • Denise, I can’t really comment, but I wonder if changing your diet, perhaps in parallel with the medical recs of your doctors, could eventually decrease or eliminate your need for the medication?

  • Ron

    Hi Peter. My (short) story is similar to yours. I had most, if not “all”, of the metabolic syndrome conditions a couple of years ago, including a father that had his first heart attack at age 48. At age 50, I started becoming more concerned with my well-being as I started, what I thought at the time, rapidly deteriorating health-wise. Hypertension (w/ medication), for the prior 15 years or so was @40 lbs overweight (considered obese at 30 BMI), 38-40 in. waist, avid runner running 25 miles a week, I’m fairly certain that my BG was constantly running high (never checked back then, but do now!), triglycerides constantly above 150 and cholesterol NEVER below 230 in my life, even when I was thinner (w/ low ratios)…

    In any event, I started the fasting lifestyle, fasting @20 hrs a day, cut carbs to <100 grams/day on average and I lost 35 pounds in about 8 months, and more importantly have kept it off! Waist: 33 in., cholesterol now at 193 (3.4 ratio), triglycerides down to 47, BP averages 125/70 (off meds!) and now only run about 10 miles a week just to stay active and I've never felt/looked better in my life and I have people like you, Gary Taubes and a few others to thank as you are all great inspirations! Thank you for your personal hard work and devotion to these endeavors and I wish you good luck in the future.

    I am one of your statistics… please feel proud, Doctor… you're changing lives!!

    • That’s a great story, Ron. Congratulations for your success. Please share it with others.

  • shelley

    Hello Peter,
    I’ve been reading your blog since I found it a few weeks back and I really appreciate the technical explanations you give in your blog posts. My own personal experiments with a sample size of one (me) bear out much of what you say.
    I ran across a newsarticle in ScienceNews 18 May 2013 discussing a study by Robert A Koeth et. al., “Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis” Nature Medicine 19, 576-585 (2013). (http://www.nature.com/nm/journal/v19/n5/full/nm.3145.html)
    Thy found that intestinal bacterial used the L-carnitine found in red meat to produce a byproduct called trimethylamine N-oxide (TMAO). They then found a link between high blood levels of TMAO to risk of impending heart attack and stroke.
    As a person with a high family risk of heart attack, this article has me worried.
    What are the chances that in the future you could add this article or subject to your queue and help explain what it really means or why the study is flawed for those of us more technically challenged.
    Thank you for your time.

    • Shelley, I linked to two great posts on this on the FB page back when they came out.

  • Tim

    Thanks Peter for your work and sharing it with us on the internets…

    Question about an n=1 experiment I just did. During a recent IF (skipped breakfast and lunch), I checked my Blood Glucose every 2 hours. Background – obese with prediabetes, low carbing. The readings were always between 102 and 113 (average 106). Checking my log for all my BG readings, about a 25% are under 100.

    During my fast, there was plenty of time for insulin to bring down my BG to a lower range (80-95). This would suggest that something is keeping my BG at a higher setpoint that a normal person. Right?

    Could it be that my body wants to keep my blood sugar higher so that there is more glucose available for my brain? Low carb helps keeping my postprandial BG lower, but what can I do to keep my preprandial/fasting BG as low as possible?

  • Lauren Cooper

    do you recommend one type of testing to others as it pertains to ketone testing? Blood vs urine?

  • Janet Patterson

    Just wondering if you have read “Wheat Belly” by MIchael Davis, MD. and what you think of it. Thanks.

    • Yes, and I know Bill Davis (not Michael) personally. Very good guy and excellent doctor. This was not really the book he wanted to write, but the publishers made him tone it down and simplify it overly to reach a broader market.

  • Hi Peter,

    Thanks for the great presentation. Just wondering, is there a reason you exercise before eating? Also, I noticed in your presentation, that following your second meal, your Ketone levels appear to decrease. While in the periods following both breakfast and dinner your Ketone levels rise. Why is that?

    Thank you in advance.

    • I need to get my workouts done early in the day, or they won’t get done. BHB goes down if HGO goes up; BHB goes up if the workout is not particularly intense (typically below 50-60% of VO2 max). See 2 part series on interplay of exercise and ketosis from about a year ago.

  • Maria

    I loved this! Thank you! I have been in ketosis for over a year now, and I don’t think I will ever go back to carb burning.
    Can you tell me how blood CO2 relates to exhaled CO2? My blood CO2 is chronically lowish, but since burning fat produces less CO2 than burning carbs, this could be considered normal and expected, correct?
    Thanks again!

  • Calvin

    Just came across this video on another blog so just started following yours today. I haven’t read all of the comments and don’t know much about the ketonic process other than what I learned from your talk. I do know when I cut carbs and worked out hard, my sweat had an ammonia smell. Is that a sign of ketosis or something else? I have read conflicting points on the internet and would rather ask you. Thanks for the great info!

  • Peter

    Peter: THANKS so much for a fantastic and incredibly information packed blog! I was wondering about this study by Susanne Holt, http://ajcn.nutrition.org/content/66/5/1264.full.pdf, which I think you have referenced in previous posts, about all foods, even protein, causing spikes in insulin. My question is this (I have scoured your site and many others, plus Gary’s GCBC and Lustig, and have not found an answer): if insulin does in fact go up following protein ingestion, do we even care as long as there is not glucose floating about due to eating carbs? In other words, does the low carb, high fat, not-too-high protein approach protect from insulin spikes from protein ingestion?

    • Insulin is only part of the story. An insulin spike in the presence of protein is more like to drive anabolism of muscle than, say, DNL. Also, there is a quantity difference between “excess” protein and “excess” carb, though Bray et al, showed in early 2012 (JAMA, I believe) that high protein overfeeding will lead to adiposity.

  • David Harley

    Hi Peter,

    Great video, I’ve been speaking about this to swimmers for a while now and this really sums it up. I’m doing a English Channel relay next week and have been in ketosis for a while now. I completely get what you say about loving the feeling of being in ketosis. I also am using superstarch as they finally have a UK supplier and it was really worth waiting for. One unexpected bonus has been the complete lack of hunger for hours after swimming. Usually, after a 2 hour swim, I’m fairly hungry but now, I can not eat for hours afterwards and not even notice it. I wonder if there would be a market for this as a meal replacement?

    I would really be interested to see a solo channel crossing on superstarch. I know Prof Noakes has said that in theory you could do a solo without feeding. Any thoughts on that?

    • I think it would be possible, but only at a very low RQ, basically 0.72-0.73 and it would require a pretty good day for a sub-11/12 hour crossing. Superstarch would be better suited for a channel crossing than the garbage I drank when I was swimming channels.

  • Gaston


    Excellent presentation! You did a fabulous job keeping it at the right level of detail for someone that is not a physician, and you really got me thinking about ketosis.

    I have cycled through “slow carb” and “paleo” versions of low carb diets with great results on body composition but found varying degrees of difficulty in sustaining them due to extensive travel and general time required to plan/prep meals.

    Do you have specific guidance around sustaining a ketogenic diet when traveling and have you found any downsides to being in ketosis for prolonged periods of time?

    Thank you!

    • I do have a strategy for staying in ketosis while traveling (i.e., basically needing to purchase most food). Probably need to blog about it at some point. Biggest drawback I find to sustained ketosis is food fatigue.

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  • Andrew Logan

    I have a question about BHB levels achieved in the adapted ketotic state as to whether it is a case of ” some is good so more must be better”. Are there additional benefits that accrue as you get higher levels of blood ketones? I guess if one was ketogenic for therapeutic reasons such as neurological or mitochondrial disease or cancer mitigation one might assume the answer was yes, but even in epilepsy management which appears to have the longest track record of research, there is a very little on dose vs response, and only some suggestion that there is a “threshold” for effect.
    For the average healthy person who is on a KD, is there any benefit in pushing for as high levels as possible? I usually toddle along at around 1.5 to 2.5 mmol BHB, but last weekend managed to get up to 5.6 by dint of a 24 hour fast followed by a fatty lunch and lots of coconut cream and a 16km run – doable but maybe it’s unnecessary. What do you think?

  • Dmitriy

    Hi Peter,

    NuSi is on an amazing mission and best of luck to you.

    I have a question about your talk: will a ketogenic diet still be beneficial for someone who does not exercise that much?

  • Shaun

    Hi, Peter.

    I wanted to comment to request that you add the video in this post to your media page. It’s a really great video and when I went back to rewatch it today I couldn’t remember which post it was in. That’s going to become more of a problem as you continue to post new great content.

    Thanks for what you do!


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  • ferro silvio

    First of all, congratulations for thinking outside the box and trying to support your findings and claims with real science.
    I’m a Family Doctor that likes to train for triathlons. But I’m really not as efficient and dedicated as you are. I did, and do struggle with my weight. My solution that brought me down 15 Kg was a protein diet. With the same goal, getting into ketosis. Enough protein to not lose muscle tissue and ketosis, so I was not hungry. Also no carbs but differently, also very little fat. So all together, very low in calories. My goal was to get down 20 Kg. Instead I gained 2 Kg after the diet and every holiday I take I gain 4-5 Kg. So always back to protein after a holiday.
    I’m now back to my diet and trying your approach. Just to see if I can eat more and still get to my real goal of losing another 9 kg en arrive at 8-10 percent fat (who knows even less). After my diet I did a dexa that told me I was 67 Kg and 19.1percent fat. So there is work to do.

    After your presentation I have a few questions. I also did a cycling test and my RQ starts at 1.04 and ends 1.51. My vo2 max is 3032 ml/min at that time my VCo2 was 4487. Vo2/Kg=45. Also my max output was only 260 watt. So I’m not a very good trained athlete and certainly not at the time of the test.

    But the question is, is my RQ this high because I was eating carbohydrates? (no diet at that time) Or is this also the difference in fitness? You see I like numbers too, so I will do a new dexa and cycling test to compare my numbers.

    Second question is, do you have to train your body in ketosis to learn it to burn fat? Or does this ability come automatically once your body is producing enough ketones, just because you do not eat carbohydrates anymore, and eat enough fat.

    And, final thought, looking at this as a diet will still make it difficult for a lot of people to keep their results. Because carbohydrates are everywhere. And I (still) like them. That’s why I gain so much weight during a holiday. Hopefully our industry invests in wheat alternatives (like the sweeteners for sugar) so I can keep eating Cake and muffins. And once in a while I have to eat french fries.

    • RQ is largely driven by dietary composition. The lower the RQ, the less CHO and more fat. Fat has RQ of 0.7, protein and BHB higher, CHO closer to 1.
      Very much agree with your last point. It’s tragic that some of the foods most harmful to at least two-thirds of us are the cheapest, most ubiquitous around.

  • Dan Clugston

    Hi Peter,

    Thanks so much for generously sharing your work. I really enjoyed the delivery and content of your talk.

    From the perspective of a lay person to nutrition, but a competitive powerlifter who needs to dabble in keto here and there, it’s utterly refreshing to come across exploratory research like yours, that is so thorough but also clearly and openly presented.


  • Diego Ventura

    Hello Peter

    Usually im just a lurker in your blog and several other regarding topics about nutritional ketosis, cuantified self, etc.

    But this talk was so amazing that I had no other choice but to congratulate you.

    You seem like an amazing person.

    Thank you for your honesty and inspirational work.

    Kind Regards


    • Diego, very kind of you to say. I’m glad the talk was helpful.

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  • John

    I have PD (diagnosed 14 years ago) and have been treating with 12 TBS coconut oil daily.. A ketogenic diet is much too complicated to do on my own. I use the post-exercise ketosis process every morning to stop my tremor by briskly walking 5km in 50 min. You posed an interesting question and I didn’t find the answer on your blog. Can carbohydrate and high ketone levels co-exist ? If so what foods should I eating ? My conclusion is that protein and high quality carbs are the best answer for a non-ketonic diet.

    • It’s relative, but under 2 conditions I can think of: very LONG and vigorous exercise, and with the use of exogenous ketones.

    • John

      Since I am already supplementing ketones levels with coconut oil, it would seem then that the only way to maximize the ketone therapy is to reduce carbohydrate consumption.

    • John

      I have been ingesting coconut oil for five months, currently a dosage of 10-12 TBS per day. Two more questions:

      (1) Am I already in a ketogenic adapted state ? Or do I have to be cold turkey on carbs for this process to occur

      (2) Would it be prudent to scale back my exogenous intake while pursuing nutritional ketosis.

  • christie

    Hi Peter,
    I am learning so much form you site and from Gary’s book, Good Calories, Bad Calories. Thank you.

    Question: I have been low carbing since 11/3 when I discovered my a1c was 5.8, so it is new for me.
    In that short interval my a1c has gone to 5.7 and my lipid panel went from meh to great. But,
    my heart rate has gone up a lot. Previous resting rate around 60, now it is 80. Is this an electrolyte thing? I have added Mg (500mg), K (trying to get to somewhere near my pre-low carb high fruit intake), Ca (500 mg) and more salt in food, etc. What are your thoughts?
    Thank you.

    • I can’t really say, Christie, but my first guess would be plasma volume contraction — basically dehydration. You probably need to be drinking more water.

    • christie

      Thank you Peter, I will give that a shot.

      Thank you again for all the wonderful information you are sharing; it is helping me in my quest for deeper understanding of my metabolic syndrome and helping me to implement changes that are improving my health.


  • John


    I’m getting fasting ketones 2-3 mM/l and fasting glucose 65-75 and still improving. I am not totally without keto-adaptation symptoms yet so I still have a way to go.

    I have one burning question however. Can you identify how you managed to get such low fasting glucose and high fasting ketones on some days, as shown in your scatter plot ? Was it the long extended Sunday bicycle rides that showed up the next morning ?

    • Almost always the result of sustained high-end aerobic activity.

  • Robin McFee

    Can anyone recommend the best way to measure blood ketones or beta hydroxybutyrate at home? Which home testing systems are easy to use and accurate?

  • Jeff Johnson

    Precision Xtra ketone and glucose meter is still being given away free – you get the ketone strips online from Canada(least cost)


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  • DareV


    In your blog entry about your bike vo2 experiment and ketosis (no comments enabled there so thats why Im asking here). You started with “it seemed possible that I should be able to get by utilizing far more fat than glycogen for aerobic activity”. Does this mean that our muscles only burn glycogen – glucose stored in muscles and are not able to burn glucose in blood?
    I greatly care about anaerobic performance (strength and high interval related) and am studying about it last couple of days. I’ve learnt that under heavy load muscles first rely on ATP-CP stores and then start to oxidize glycogen without presence of oxygen, to produce ATP as fast as possible (regular glycogen oxidation – glycolytic is not fast enough). That is most likely the reason why fats cant be burnt during anaerobic activity because cells cant convert it to ATP so fast as they can glycogen. I also understand glycogen needs to be replenished before a next workout/session otherwise performance might suffer as you also pointed out in your blog about carbs and ketosis.
    What I cant figure out and finding info on it is very hard; what about liver glycogen and its relation to anaerobic exercises. Does anaerobic activity and recovery after it depends on liver glycogen, eg does it need to be full for optimal body functions? Or is this where gluconeogenesis comes into play and does the job?
    I’ve read that there are some muscles in intestine system only work on blood glucose, true? Also in the lecture in this video you’ve shown a graph from a man fasting for 40+ days and his blood glucose quickly dropped but then remained the same. In the video you said you will not get into explaining why this happens, but did you explain this somewhere else, I am also eager about it.

  • Jeff

    Hi Peter,
    Thanks again for all the excellent information on your blog! I’m going to try the 10 day challenge from the Fed Up documentary, and I’ll see if I can stick with eliminating added sugars for once. Alas, I eat mostly fast food, and I’m worried about CAD, yet I’m only in my early 30s. Having anxiety issues doesn’t help the matter. Anyway, regarding endurance exercise, a lot of people in the paleo talk about intense exercise for a brief period of time, e.g., 20-30 minutes. I’ve heard Art DeVany say that long distance running and such can damage the heart and is extremely dangerous. Is there any evidence to back this up? I used to run and cycle all the time, which seemed to reduce my stress and anxiety levels dramatically. However, I hardly exercise because of some of the negative information that I’ve read. Thanks for your time!

  • Martin

    Hi Peter,
    I want to ask you when you did the experiments in metabolic chambers? I guess it was at the beginning of 2013. Am I right?


    P.S. I would like to read some series of articles about your experiences from that…

    • Yes, in 2013, between February and April I think.

    • Martin

      Thanks you, because now I am writing book in slovak language about ketogenic diet and connection between keto and exercise. Much stuff I have used from your experiments so I want the detailes 🙂 Also I have used some stuff from Ben Greenfield, Barry Murray – http://www.optimumnutrition4sport.com and from Dr. Phinney and Dr. Volek.

      Now I am in ketosis and testing some things at myself. Especially effect of ketosis on proffesional athlete because I am profi soccer goalkeeper.

      My friend, who cooperate with me on the book, practice long-term concept Warrior diet (1 big meal per day at evening) by Ori Hofmekler and he is freerunner and parkourist and train very anaerobicly. He is very strong- https://www.youtube.com/watch?v=R1Zr1Wcz9Dw

      He was lately on spiroergometry after 15 hours fasting and his results was amazing. His ketones was 0,5 mmol/L which is his normal level of BOHB. His VO2 max is only 53.9 ml/kg/min but he reached it at RQ 0.95. He have reached anaerobic threshold at 88% VO2 max and RQ 0.67. He have burned 123 g of fat per hour. Aerobic base (RQ 0.85) reached at 49.8 VO2 (92,6% his VO2 max). It is crazy because he don´t eat ketogenic diet although he is close to it.

    • Martin

      For our experiment´s purposes I want to ask, where can we buy devices which you used in your test for VO2 max, AB, ANT and so on. I think foto in this post – http://eatingacademy.com/how-a-low-carb-diet-affected-my-athletic-performance

      Thank you

  • Martin

    Hi Dr. Attia, I would like to know which pace you held during your bike ride after 24 fasting and then 6 hours riding. In interview with Dr. Eenfeldt you said that it was your record but you didn´t say what the pace you held.

    I guess average 60% your VO2 max. Am I correct?

    Thanks for your time

    • I think average power was about 180 watts and normalized power was about 200-220 watts, so this was not a “brutal” ride, but it had some big efforts on climbs.

  • Rick

    Dr. Attia,

    I currently an practicing Functional Medicine with my wife in Colorado and have experience w/ endurance athletes.
    I have two questions:
    1) Did you look at cortisol levels pre and post switching to ketogenic diet ?
    2) Did you do complete cardiac, nutient, mineral, or biochemical profile testing pre and post ketogenic diet ( eg: Neutraval, Spectrocell, or Health Diagnostics ?)


    thanks Rick

    • Unfortunately pre-ketosis I was only doing VAP, so I only have info on calculated apoB, not measured apoB or measured LDL-P, which I now use.

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  • Will Stoddart

    Hi Peter,

    I enjoy reading all of your blog posts (‘Fat Flux’ has to be one of the best expositions on weight gain/loss that I’ve ever read).

    I thought you may be interested in an example framework for analysing personal data that my brother and I have been working on, with an example. It’s also a good example of Feynman’s first principle – you must not fool yourself.


  • Mike Akers

    Hi Peter! Thanks for the amazing blog and great talk. I’m an engineer, so I really like how you strive to get a “down to the metal” understanding of how your nutrition affects your body. It’s really helped me understand how ketosis works in my own body.

    I have a question about RQ: You mention that it can be used to figure out what substrate the body is using to produce energy, but I’m unclear why you can make that correlation. Is it simply that burning fat requires a lower ratio of Oxygen consumed to CO2 released?

    • Yes, it’s based on the study of indirect calorimetry. By knowing the amount of CO2 produced and O2 consumed you can determine the ratio of fat and CHO utilized.

  • Prakash

    Wow! what a talk…what a beautiful thoughtful and though provoking presentation….all the numbers and facts were perfect for making the case….and you have very good presenatation skills as well, trying to keep it humble and in perspective without sounding dogmatic or prescriptive…

    I am in ketosis as well…my diet is
    fatty meat, eggs, ghee, coco oil
    little bit of very well cooked veggies (I dont do well with fiber due to gut damage from extensive fiber use in the past)
    supplements for calcium, magnesium, vit c, fish oil, vit d

    love the ketosis. my mind is sharp, calm. My gut feels calm. I can go for hours without feeling hungry and cranky.

    I include exercise on and off. Mostly biking and some strength trainining. I notice that when i strength train, i dont need to fuel myself with carbs before or during. when i lift weights, i feel so strong to lift them…no wobbly stuff…

    yet, a lot of improvement pending on the muscle gain area…will get there…

    thanks again and i love your blog and your scientific aptitude,


  • Rob Pellow

    Peter – love all the research you’ve put out on this! Two quick questions – i feel best at a ketone level between 2.5-4 but have seen few articles or posts of people at the level. I’m two weeks into ketosis and as i become more adapted my ketones continue to rise (almost daily). Obviously north of 8 is dangerous territory but is hovering around 4 or 5 abnormal?

    Additionally, is there a preferred method to coming out of ketosis while avoiding ‘keto flu-like’ symptoms?

    Thanks – Keep putting out great work!!

  • Super non-linear path and not at all planned out. Was fully invested in pursuing PhD in aerospace engineering when change of heart set in and switched to medicine, which meant going back to do start from a post-bac.


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