For reasons I’m still struggling to understand, the idea of “nutritional ketosis” (NK, to be distinguished from starvation ketosis, SK or diabetic ketoacidosis, DKA) is often discussed and debated in much the same way as religion or politics. Perhaps this can be said of all nutrition, which is a shame.  Nevertheless, in my continued defiance of such sensitive topics, I’d like to add another layer of complexity and nuance to this discussion.

The “rule of thumb” for NK is that caloric intake is determined as follows (this excludes a subset of ketogenic diets known as calorie-restricted KD which, as the name suggests, is specifically restricted in calories):

  1. Carbohydrate (total, not “net”): less than 50 gm/day, but ideally closer to 30 gm/day
  2. Protein: up to 1 to 1.5 gm/kg, but ideally below about 120 gm/day
  3. Fat: to satiety

Let me illustrate what this looks like for Joe (left), Jane (middle), and Jeff (right — an example of a calorie restricted KD), three hypothetical people in NK — but each with different caloric requirements.

 

As a general rule, as caloric requirement increases the proportion of calories derived from carbohydrate and protein decreases (and the contribution of dietary fat increases), even while absolute intake of carbohydrate and protein increases.

Anyone who has bought a blood ketone meter knows how tough it can be to get “into” ketosis by carbohydrate restriction (since everyone asks, I use the Abbott Precision Xtra meter which uses two different strips: one for glucose and one for beta-hydroxybutyrate, or BHB).  Most practitioners consider the minimum threshold of NK to be a fasting serum level of BHB above 0.5 mM.  I’m a bit more stringent in my practice and like to see fasting BHB levels above 1 mM.   To give you a sense of one person’s numbers (mine), over a 6-month stretch in 2013, when I was in NK, my mean (i.e., arithmetic average) morning fasting level was 1.7 mM with a median value of 1.4 mM.  The highest morning level during that period was 5.2 mM.  (The highest morning level I have ever measured in myself is 5.7 mM.)

But, it took me a long time to get it right, especially since at the outset of my foray into NK I was consuming between 4,000 and 4,400 kcal per day.  (My average daily caloric intake for weight stability was about 3,800 kcal per day, which was validated by doubly-labeled water.)  I could still easily “fall out” of NK.  For example, on my daughter’s 5th birthday she insisted I have some of her tikka masala (contains lots of sugar), naan bread, and mango ice cream.  How could I say no to a birthday girl who insisted on going to the nicest Indian restaurant in San Diego?  As to be expected, the next day my BHB was 0.2 mM, and it took me 2 days to get back above 1 mM.

Here’s a little secret I’m about to let everyone in on… I like carbohydrates. I love sushi (though I now mostly eat sashimi).  I love Indian and Thai food, though I prefer to make curry myself to keep sugar out.  I make (and eat) the best hummus this side of the Nile River. I’ve figured out how and when I can eat them to meet the following conditions:

  1. Stay in NK (except on a few occasions like my daughter’s birthday);
  2. Increase my anaerobic performance;
  3. Preserve most (but not all*) of the benefits I enjoyed when I was much more strict about my ketogenic diet.

How, you ask? By learning to calculate my glycogen deficit.

(*) For me, the leanest body composition I achieved as an adult was in strict NK with no attempts to do what I’m about to describe below.  Since I’m not a model and nobody cares if my body fat is 7% or 10%, I’m happy to be a little less lean if it gives me the flexibility to increase performance and live a slightly more sane life.  At least for now.

PLEASE NOTE: I have never suggested, and can’t imagine I ever will suggest, that a KD is “best” or “right” for everyone.  What I describe below may seem extreme, both in the amount of work required and the actual application.  I fully acknowledge that (1) this is a highly analytical approach to eating, and (2) that I’m a “freak” (my wife’s words, not mine). I certainly don’t do this often, unless a lot is on the line (e.g., a big ride), but I like having this technique in my armamentarium.

If you’ve watched my presentation from 2013 at the IHMC, then you’re familiar with RQ.  Through years of metabolic testing I have a pretty good sense of my RQ at any moment in time – when I’m sleeping, when I’m sitting around (most of the time), when I’m riding my bike at 200 watts, when I’m riding my bike at 400 watts, when I’m lifting weights, etc.  This allows me to calculate what proportion of my energy I derive from glycogen and what proportion I derive from fatty acid.  Consider the following example:

If I ride my bike at an average of 185 watts (you’ll need a power meter to infer this) for, say, 2 hours, I know my average RQ is between 0.76 and 0.80.

The approximate formula is %CHO = 3.333*RQ – 2.333, which can easily be derived from the observation that %CHO utilized increases linearly from 0% at RQ 0.7 to 100% at RQ 1.0.

Furthermore, I know my VO2 at 185 watts is 2.9 liters per min, which means (using the Weir formula which I presented previously) my energy requirement was about 14 kcal per minute, or 1,680 kcal over 2 hours.  Hence, of these 1,680 kcal needed to pedal 185 watts for 120 minutes, 336 to 554 kcal came from glycogen.  In other words, I utilized between 84 and 138 gm of glycogen.

(By comparison, several years prior to being in NK, this effort in me would have taken place at a slightly higher VO2 – closer to 3.2 liters per min – and at a much higher RQ – between 0.90 and 0.95 – meaning the exact same work output would have required somewhere between 300 and 400 gm of glycogen!  That’s a real state of metabolic inflexibility.  Basically, I was entirely dependent on carbohydrates for energy.)

Since the first metabolic priority for ingested carbohydrate is glycogen replenishment, I can, in this setting, consume probably somewhere between 60 and 120 gm of carbohydrate following this ride and stay in ketosis.  Why? Because those carbohydrates are prioritized to replenish my glycogen stores AND I am highly insulin sensitive.  Note the *AND* in this last sentence. (The especially astute reader will realize some of this glycogen debt will be replenished by protein and glycerol, the latter of which is liberated by lipolysis – see post on fat flux for a primer).

Clearly I didn’t consume this amount of carbohydrate on my daughter’s birthday, so why was I out of ketosis the next day? Because my glycogen debt was not high.  Of course, I knew this and didn’t really care.  But, if I know my wife wants to go out for sushi one night, and I know she’s going to make me eat a California roll, I can “rig it” such that I show up to dinner with a glycogen debt appropriate enough to enjoy them without significantly interfering with my liver’s BHB production.

Extreme example

At one point, I did two tough bike rides on consecutive days.  Each day we rode 110 miles under challenging conditions.  Over 6,000 feet of climbing each day and very strong winds, which were either headwinds or cross-winds.  On top of this, we rode pretty fast. For the purpose of illustration I recorded everything I did and ate on the second day, which I rode a bit easier than the first day.

The second ride took 6 hours and 5 minutes.  My average normalized power output was 225 watts, and arithmetic average power output was 184 watts.  Based on mechanical work output, this required about 5,000 kcal.  Factoring in the other 18 hours of that day, my total energy expenditure was about 6,800 kcal for the day, obviously not an average day. (A detailed explanation of where the extra 1,800 kcal were expended is beyond what I want to get into now, but it’s basically the energy required to keep me alive – transport ions, contract voluntary and involuntary muscles, etc. — plus move me around, and digest food).

So what did I eat that day?

  1. Breakfast (pre-ride): 5 scrambled eggs, 2 sausage links, 3 pieces of bacon, coffee with cream.
  2. In ride nutrition (I spread this out over 6 hours): 14 oz (not a typo) of salted cashews, 2 Quest bars, 1 peach, 1 apple, 6 bottles of Biosteel High Performance Sports Drink, water. (Since I know someone will ask, I did not consume super starch this day since I was craving cashews as my carbohydrate source and was craving more sodium, given the 90+ degree temperature.)
  3. Late lunch/early dinner (post-ride): 2 oz ham, 3 oz pulled pork, large salad with oil and vinegar dressing, 2 slices of cheddar cheese, 6 mini hamburger patties, 2 tomatoes.

What did this amount to?

  • Fat – 351 gm, or 3,160 kcal of fat
  • Protein – 245 gm, or 980 kcal of protein
  • Carbohydrate – 321 gm, or 1,284 kcal of carbohydrate

(I used package information and Nutritionist Pro software to calculate this.)

Hence, on this day I consumed about 5,400 kcal in total at the following ratio:

  • Fat – 58%
  • Protein – 18%
  • Carbohydrate – 24%

By all conventional wisdom I should not have been in ketosis the next morning, right?

The following morning, my BHB level was 2.2 mM and blood glucose was 5.1 mM.

Teaching point I can’t resist: Following 2 days of significant caloric deficit, about 3,000 kcal in total, I should have in theory lost about a pound (mostly fat, possibly some muscle) which would have been noticed on a scale.  Instead, I gained 8 pounds over those 2 days! Sure it was mostly water retention, both from the glycogen (small) and the fluid accumulating in the interstitial space (“thirds space” fluid losses, large) due to a systemic inflammatory response.  This happens under extreme conditions of exercise.  In fact, the harder I exercise, the more weight I gain, transiently.  I am at my absolute lightest following 2 days of travel (i.e., rest).  So before freaking out at the sight of the scale, keep in mind that most day-to-day weight movement in our bodies is indeed water movement into and out of the plasma and interstitial space, respectively.

What’s my point?

Context matters!  If I ate even one-quarter of that amount of carbohydrate and two-thirds of that protein on a normal day – say, 2.5 hours of riding or 1.5 hour of riding followed by 1 hour of swimming, or a day of travel with no exercise – I would have been out of ketosis for two days or more. (Of course, my appetite on those days would not have allowed me to eat 5,400 kcal without feeling sick, but I won’t get into that until a later post.) But on this day, with these glycogen demands, I was able to maintain the perks of ketosis AND glycolysis simultaneously.

There are days, though, when I overshot my glycogen need and end up with a low BHB and high fasting glucose the following morning. Conversely, there are days I underestimate my glycogen depletion and wake up with very high BHB levels and very low glucose levels (i.e., BHB levels higher than glucose levels, when both measured in mM).

Final thoughts

I felt a bit like I was in unchartered territory because the literature on nutritional ketosis hadn’t really (to my reading) explored this level of extreme activity.  In future posts, I may write about other experiences and self-experiments, including my experience with exogenous (i.e., synthetic) ketones (which I did not use on this ride, but have experimented with on other rides – no, this is not “raspberry ketones” or other such gimmicks).

2017: You can read about one of my earliest experiences with exogenous ketones in this post.

Are carbohydrates necessary to produce 225 watts or more for hours on end? Yes. But, the key is knowing how much you need and when to take them.  A lower RQ at a given level of intensity means less demand on glycogen. In my experience, working with athletes and non-athletes, most tend to make two errors (for lack of a better word):

  1. They over-estimate their carbohydrate requirement, and/or
  2. They forget that no factor influences RQ – and therefore substrate requirement – more than dietary composition during lead up to event (or “life”, which is sort of the ultimate event).

Know your engine, first.  Then fuel it appropriately.

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595 Comments

  1. Chee Fong says:

    Dear Dr Attia

    I know you are a busy man, so I will try to keep this as short as possible. I must say right off the bat, that I am not like the average reader of your blog, who are admirably intelligent, so please forgive any statement that reeks of ignorance. I would like to draw attention to Advanced Glycation End-products (AGEs). I first came across AGEs in Dr William Davis’ ‘Wheat Belly’ book. They are said to cause anything from atherosclerosis to dementia. They are essentially useless debris that result in tissue decay as they accumulate in our body, purportedly contributing to the aging process and are perhaps a major cause of diabetic complications (neuropathy etc.). They are also found in much higher amounts in older people. AGEs are also a by-product of high blood sugar. To better describe AGEs, I would like to quote an excerpt from ‘Wheat Belly’ : “The greater availability of glucose to the body’s tissues permits the glucose molecule to react with any protein, creating a combined glucose-protein molecule. Chemists talk of complex reactive products such as Amadori products and Schiff intermediates, all yielding a group of glucose-protein combinations that are collectively called AGEs. Once AGEs form, they are irreversible and cannot be undone. They also collect in chains of molecules, forming AGE polymers that are especially disruptive.2 AGEs are notorious for accumulating right where they sit, forming clumps of useless debris resistant to any of the body’s digestive or cleansing processes.” INTERESTINGLY, AGEs are also found in high quantities in animal products (meat and fats). Here is a paper about AGEs and their content in various food, https://www.ncbi.nlm.nih.gov/pubmed/20497781. So I wonder, if a diet like yours, which is high in saturated fats, may also yield a high AGEs content. Bacon, especially, is extremely high in AGEs. High temperature cooking methods also dramatically increase the AGEs content in food. I also practise a diet similar to yours, which is LCHF. I worry that, such a diet may have the unexpected disadvantage of coming with a high AGE content, and may thus increase the risk of atherosclerosis (and other complications). May I suggest that you take AGEs into consideration in your NuSi efforts ? What is your take on this ? Sorry for the lengthy post and thank you for your time.

    P.S. You are a great inspiration, it takes tremendous courage to admit one is wrong and go against the prevailing dogma and carry out self-experimentation. If only we have more people like you in the medical profession.

  2. Joe says:

    Hi Peter,

    Thanks for all the time and passion you put into this over the years. Over the past few months I have successfully lost 35+ lbs (28 fat) through NK. After studying much of your blog I am now adjusting further by increasing my fat intake and lowering my proteins. Question: I have a hunch that human ketones (acetone, acetoacetic acid) are not chemically the same as raspberry ketones (C10 H12 O2). If one were to ingest true, pure raspberry ketones (C10 H12 O2) would that provide any physiological benefits identical to human ketones? (I was considering an experiment by using raspberry ketones for the 2 days following cheat days to try to maintain my ketone level and responses while my body adjusts down from the carbs of a cheat day).

    Thanks!
    Joe Richardson

    1. Peter Attia says:

      Raspberry ketones are really just a gimmick. If aspiring for NK, berries are fine, but need to be kept in modest doses.

  3. John Theobald says:

    Staying in nutritional ketosis is sometimes counterintuitive. Using the calculator on the above website which give the ketogenic ratio for example, If a person went over in carbohydrate and to a lesser extent protein they could still stay ketotic if they compensated with more fat. Even though this would be much higher in calories they would stay in nutritional ketosis. The ratio correlates strongly with the blood ketones.

  4. Norm says:

    In an attempt to get into ketosis many people have experienced pounding heart especially at night.
    Why this could be? Thyroid? Electrolytes? And how to tackle it?
    Thanks

    1. Peter Attia says:

      Impossible to say without a workup, Norm. That’s why I can’t practice medicine via a blog.

  5. Norm says:

    That’s true Peter. On the other hand what people like yourself are doing on blogs is way better than what many doctors are doing in practice. Like increase in LDL-C on a low carb diet, pounding heart issue also seems quite puzzling for some people, especially when adding carbs back seems to fix the problem in both cases for many people but they are kicked out of ketosis and stop losing weight. Some have reported to have fixed heart pounding by adding sodium also. Not sure if one can supplement more than 2-3 grams of sodium if this much does not work?

    1. Peter Attia says:

      Magnesium helps with potassium, also, which is often the problem.

  6. Nonna says:

    You mention a metabolic response to inflammation as a result of exercise and refer another commenter to systemic inflammatory response syndrome. I searched your web site and your Coming Soon page and didn’t find anything regarding the metabolic response to infection or inflammation. Thus my question: can an infection knock one out of ketosis — cause the BK to drop down to 0.2 and the BG to remain higher than baseline — and for a person to gain weight, even when adhering to a LCHF diet?

    Thanks!
    Nonna

    1. Nonna says:

      I meant to say — gain weight that is not just water weight, but weight around the waistline. And in rereading your post and some of the comments I’m thinking that the SIRS response to inflammation from exercise is not much different from a metabolic response to infection? Just would like it see it all fleshed out in a future blog post. Plus maybe the implications are that when one is having an SIRS response to infection, perhaps it’s important to introduce some carbohydrates in the diet just as athletes do in their glycogen recovery phase?

      Sorry if my questions are garbled.
      N

    2. Nonna says:

      Sorry to be a serial commenter! I need to continue to clarify: when I’m talking being kicked out of ketosis and gaining weight due to infection, I don’t mean a transient experience but rather one lasting 2 -3 weeks. Also I researching metabolic responses to infection I stumbled on the following article from 1981 and don’t have the training or background to interpret it fully. It does seem to be a somewhat different process than what’s described in the wiki for SIRS. It suggests that there are two parallel responses to infection — immune and metabolic:
      The American Society for Clinical Nutrition, Inc
      Effect of diet on the metabolic response to infection: protein-sparing
      modified fast plus 100 grams glucose and yellow fever immunization.
      B R Bistrian, D T George, G L Blackburn, and R W Wannemacher

      Abstract

      The metabolic response to yellow fever immunization was investigated
      in four obese subjects who were consuming a protein-sparing modified
      fast plus 100 g glucose (PSMF + 100 g) for 3 wk. Fasting, 1/2, 1, and
      2 h postprandial values for insulin, glucagon, glucose, lactate, beta
      hydroxybutyrate, acetoacetate, and free fatty acids were assessed
      before and the 1st, 3rd, and 5th day postimmunization. The hormone and
      substrate response to dietary protein plus glucose was a substantial
      rise in insulin (p less than 0.005), glucose (p less than 0.005), and
      fall in free fatty acid and ketone levels (p less than 0.005). These
      results are distinctly different from the response to dietary protein
      ingestion only (PSMF) determined in a previous study which was a
      slight rise in insulin and glucose and slight fall in ketone bodies,
      but a substantial rise in glucagon. The only significant (p less than
      0.05) change following immunization in the PSMF + 100 g was a rise in
      serum glucagon on day 1. During the PSMF significant elevations in
      insulin and lactate and falls in serum ketones were noted
      postimmunization. The metabolic response to mild infection is
      dependent on the diet consumed. These differences may have a clinical
      impact when the infection is severe, but this possibly requires study
      in an experimental infection of greater severity.

    3. Peter Attia says:

      Yes, infection can easily cause an adrenal response, which increases hepatic glucose output, which can knock you out of ketosis. A server enough infection causes a SIRS response, which almost invariable leads to weight gain — virtually all of it being third-space (interstitial) water weight.

  7. Ankit says:

    Dr. Attia,
    Your information is invaluable! I had a question and I’m not sure is the right blog post but here goes. I’ve been paleo for 4 years and 6weeks ago started a keto program. I’ve noticed that my blood glucose is around 65 at any give time of the day and my blood ketones vary from 0.1-0.4 and urine ketones are not present. . I’m not sure what my body is using for fuel. I lift weights around 1-2 me a week and do Jujitsu 1-2 times a week. Can you shed some light n what my body is using as its main substrate for fuel?

  8. Marko Skoric says:

    Dr. Attia,

    I wanted to know your opinions about my training regimen. I would really appreciate your advice.

    I am a 25 years old male from Croatia and used to be a professional tennis player. Until 5 years ago, I trained 6 hours a day and my diet was of course mainly comprised of carbohydrates. It was three huge meals consisting of either cereals with milk, pastas or pizzas. Five years ago I moved to the States when I was offered an athletic scholarship to play for a university. I moved to the States and played there for three years.

    Two years ago I stopped playing tennis all together to focus on studying and went from 86kgs (which is my playing weight), to 100kgs. I kept the same diet as in my competitive days, and I think that the processed foods from the US didn’t help. I became depressed, brain fogged and was always hungry.

    My thirst for nutrition knowledge started after I read about the “Steak and eggs” diet. After a year of going strict keto (except sometimes weekend carb reloads) and lifting heavy weights, I am back to a comfortable 90kgs. I eat a huge meal in the evening and fast for pretty much 20-22 hours each day without a drop of energy. I eat lots of eggs cooked in butter or lard, red meat and some vegetables on the side. I can lift fasted without any problems but don’t think I will be able to keep this diet when I start playing tennis again this summer. I am happy to have regained metabolic flexibility but would like to incorporate carbs in my tennis regimen and keep fat burning to a maximum.

    I wanted to know your opinion about using boiled potatoes (because of high satiety index) as my only source of carbs during tennis practices (might it be enough for the sweating of minerals)?
    Would it be optimal to start playing fasted and then eat them during practice or eat them before practice ?
    Also, would you think coconut oil would be a good enough source of energy during practice under hot conditions?

    Sincerely,

    Marko Skoric

  9. Brent Rice says:

    Hello Peter-

    I have been incredibly successful in achieving some goals through reliance on your information from your blogs. Last week I took 2-3 days and gorged for Christmas. You name it, I ate it. In the past I would occasionally allow myself a sushi roll or something along those lines as a rare treat and be back in mitosis in a matter of hours to half day at most. After my Christmas splurge I was out for almost two days. Even now that I’m back in, it seems very intermittent. The only change has been glutamine, creatine and BCAA supplementation. The brand is prosource so I’m probably imbibing bird feathers from what I have read here, but I’m wondering if you have seen these supplements cause problems with staying in mitosis before. I do about five grams of BCAA during exercise and again after. Glutamine is five grams after, creatine is five grams during and five after.

    My results are probably all the answer I need but I’d like to understand why one or more of these may be causing me problems.

    Thanks in advance,

    Brent

    1. Brent Rice says:

      Excuse the auto-correct – I did not mean cell division but ketosis.

      1. Peter Attia says:

        Ha ha… I figured.

    2. Peter Attia says:

      Brent, I assume you mean ketosis and not mitosis (damn auto-correct, I suspect). This experience is pretty typical. Should resolve within a week or so. One way to speed up the process is a very long sub-threshold effort with a few glycogen-depleting efforts.

  10. Eric says:

    Hello Peter,

    Is it worth testing blood sugar?

    I have never used a sugar testing strip for the meter I have – just the ketone ones.

    I’m currently using your standard of shooting for > 1 mmol ketones after overnight fast but am wondering if and how you use sugar measurement to help dial in your ketogenic diet.

    Thx,
    Eric

    1. Peter Attia says:

      It ads some insights, but I’m not sure it’s necessary. It’s much cheaper than testing BHB, so I always do both together. I like seeing the relationship.

  11. Anthony says:

    Dr Attia,

    Watched many of your videos and read many a book on Ketosis for athletes. I am 50 years old and still play competitive ice hockey. I I weight train 3x/week. Stats” 69″ and 230lbs (LBM=176). I cannot sustain my favorite sport on 50G CHO /day. I opted to carb backload and it seems to work for hockey, but I cannot drop the 30lbs of bodyfat I would like. Hearing you lost 40lbs is inspiring. I believe I can replicate that feat.
    Just tested Cholesterol’s and Doctor is worried: Total = 251 HDL = 56 Trig = 69 LDL = 189 Non HDL = 195…
    I am trying to figure out if I am in danger here. Trig are low…but the other numbers are worrisome. Your thoughts on the NKD lifestyle and cholesterol would be appreciated.
    Would be nice if we could find Doctors in our area that are similar in conviction to you! Let’s get that going and we can impact millions.

  12. adrian says:

    Peter,

    I am a runner in ketosis and I would like to know more about this 50gm ceiling for carbs. I have seen it mentioned in many articles and books, but would like your personal view on whether there is reason to lift this theoretical max after heavy exercise. You have mentioned in another article how you can ‘afford’ an extra does of carbs for your daughters wish of eating Indian by incorporating some high intensity exercise. Can this idea be reversed, such that the body will recover better after the high intensity(or endurance) event by ingesting more carbs? If so, is there are hard and fast rule I can apply to my training, or is everyone different.

    I am only new to ketosis, but my own observation levels is that my ketosis level seems to be influenced heavily by exercise. I am have a higher level of ketones the day after heavy exercise. A day of rest produces a lower result.

    Are their any benefits that you know of to lift the amount of carbs you consume after a heavy dose of exercise. Ideally low glycemic carbs at that. I am not suffering in any way from the reduced carb intake (after my initial 2 weeks), only interested in maximizing my performance.

    Adrian

    1. Peter Attia says:

      I usually (but not always) stop when I see the word “meta-analysis.”

    2. Boundless says:

      > It is frightening to know how easily rigorously applied
      > science can be overshadowed by headlines/studies like these.

      Here’s a proposed trial that is either designed to produce no
      meaningful results, or had its protocols sabotaged along the way.
      https://www.ncbi.nlm.nih.gov/pubmed/24383431

      They plan to equalize caloric intake and glycemic load
      between the non-grain/non-dairy subjects and the controls,
      and will only know for sure what they ate at lunch.

      Real trials by NUSI are clearly needed.

    3. Boundless says:

      > It is frightening to know how easily rigorously applied
      > science can be overshadowed by headlines/studies like these.

      And even when what passes for most nutritional science trips over a significant truth, they pick themselves up, shrug it off, and re-focus on the dogma.

      Paper:
      “The Role of Persistent Organic Pollutants in the Worldwide Epidemic of Type 2 Diabetes Mellitus and the Possible Connection to Farmed Atlantic Salmon (Salmo salar)”
      https://www.altmedrev.com/publications/16/4/301.pdf

      This study accidentally managed to avoid glycemic confounding, by including 692 Greenland Inuit, who are likely on a very low carb, possibly ketogenic diet.

      Quote from paper:
      “More work is required to better understand why such high levels of POPs were not associated with increased risk of T2DM in this population.”

      The Summary makes no mention of the possibility of diet having a potentially substantial effect on health risks, and of course, shows no awareness that T2DM isn’t really a ‘disease’ at all, but just a predictable metabolic response to a full-time glycemic diet.

      1. Peter Attia says:

        Boundless, I really like your last sentence. Very nice insight. Wish more thought of it this way.

    4. Boundless says:

      > Very nice insight. Wish more thought of it this way.

      Well, thanks, but it’s shocking to think that I’m so leading edge on that. I’m just an ordinary (non-medical) citizen who has been casually connecting dots since reading Wheat Belly in 2011. What it all leads to seems evident to me.

      For what it’s worth, those two links I posted above were not the result of broad deep digging. They were just two things that popped up lately whilst I was looking for something else.

      This suggests to me, that the issues I raised (1. flawed designs and 2. general obliviousness to blaring klaxons in the data) are depressingly common in current nutrition science. This has to be discouraging to the few enlightened physicians, such as yourself, who actually read nutrition papers.

      Thanks for a very valuable web site.

  13. cmztrav says:

    Dear Dr. Attia,
    Thank you so much for all of the fantastic information you have launched into the ether. You are a gem!
    Right now I am training for an Ironman in July. (I am out of shape and working my butt off). I would really appreciate your advice to a beginner regarding workout vs. race-day fueling. I superstitiously feel that I should simply live my LCHF life during training, but wonder if I should add something on my Ironman day?
    I guess I would like to hear your view about how various carb-based supplements/foods will affect the ability to burn fat during an endurance event. Thank you!!!

    1. cmztrav says:

      Please forgive my laziness, Dr. Attia. If I could choose a full-time job of researching and encapsulating your fantastic work I would. I have gathered your advice from a video of perhaps using a slow-release glucose source for activities lasting over about 3 hours, with some salty nuts and BCAA’s. The farther my workouts progress, the greater the confidence I have in what I am doing. I know nuts work great for me and I will look into incorporating the other two items and see how it goes. I know I feel amazing in ketosis and I thank you and other info-maniacs for pioneering this field.

      I test and log my bhob’s twice a day unless I am running an even keel, so I am learning a lot as I go along. I love your approach and admire you personally for all that you are achieving. Thank you!

  14. Mihail says:

    Hi Peter,
    In case I do a high fat, low carb diet but I just can’t get to ketosis for I don’t know which reason is it a dangerous think? I mean could cholesterol level raise dangerously because my body is not adapted to ketosis? Is it worse then a normal diet, high carb low fat?
    I know HFLC in ketosis is very good but I am nut sure how is it in this area.
    Thank you.

  15. Paul says:

    Hi Peter,
    Amazing info available on this site. Thank you
    I have a question or would like your opinion on my eating/nutrition for an eight day mtb stage race I will be taking part in. (The cape epic). I have been on the high fat low carb diet for 9 months now. I have been training for t)his event since November and have done all my training on no carbs only water on the bike. Many training rides over 6 hours, two to three days in a row. We now getting to the high intensity training phase. The question I have is do you think we can ride for 8 days with only a small amount of carbs after the day on the bike as per our normal high fat low carb diet. Or do we need to eat carbs on the bike? Have been fine up to now but not sure how the body will cope after 8 days.

    Your opinion would be really appreciated
    Regards
    Paul

  16. Diane Stibbard says:

    Hello Peter
    I am a highly competitive female athlete, considering the low carb and high fat lifestyle for performance and health reasons. I am gluten and dairy free, and also recently grain free. I do not eat red meat however, but do eat all fish, eggs, chicken and turkey. I am very lean and have practically not body fat. I am 5’1 and weight 95lbs and have less than 10% body fat. My naturapath, who works with high level athletes, is a little unsure if this is right for me, I think more because he doesn’t have any experience with the diet and lifestyle. I think he has concerns about a female following this and also I am prone to adrenal fatigue. However, the adrenal fatigue has been due to not just the physical stress I put on my body, but I have a lot of emotional stress at these times in my life when I fell to adrenal fatigue.
    Please let me know what you think

    1. Peter Attia says:

      Diane, impossible for me know without long diagnostic and some trial and error.

  17. Braz says:

    It is absolutely awesome to find such a rigorous report on sport performance on a ketogenic state. I haven’t been doing a lot of aerobics lately and have been trying a not very strict (very much “follow your instincts” when eating) sort of warrior diet. I adored the eating flexibility it gives me and definitively want to stick to any pattern of eating that allows me to have the same freedom. I had been wondering, though, i’ld have to drop this idea when getting back to aerobicks. It’s a joy not only to now it is possible and has serious advantages, but also to have serious literature to instruct me. Keep on!

    Btw, any recommendations on warrior diet style reads? People who are for it seem to get something right, but the litterature on it is a disaster.