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The personal blog of Peter Attia, M.D.

A podcast to ring in the New Year

A podcast to ring in the New Year

Last month I did a podcast with Vinnie Tortorich and Anna Vocino. It went up today on Vinnie’s website and here is a link to it.

The interview doesn’t start until about minute 17 or 18 of the podcast, so you’ll probably want to start there, if not a bit later (say, minute 20 or so) once the intro is over.  We talk about a lot of things, in particular, physical performance and fat adaptation. Vinnie and Anna were very gracious in letting me give the nuanced answers I like to give.  And for that I’m appreciative.

The reason I’m posting this is because I’m planning to write a post on this elusive concept of fat adaptation – which I know many of you have asked about – and I think this interview introduces the concept reasonably well (albeit in a somewhat elaborate and technical fashion).



About the Author:

Peter Attia, M.D., is a physician in private practice in NYC and CA. His practice focuses on longevity and healthspan. His clinical interests are nutrition, lipidology, endocrinology, and a few other cool things.


  1. Hemming  January 2, 2014

    Hi Peter,

    Great podcast! I have a question regarding fat oxidation per minute. If someone is very low in body fat would almost all of the fat for oxidation have to come from dietary fat as the body can’t effectively tap into the small amount of stored fat? Could that be the reason why obese find it so ‘easy’ to cut carbs and still feel energized while I feel cold and tired if I’m not deliberately eating enough fat?

    • Peter Attia  January 2, 2014

      Even the leanest person has more the sufficient fat stores to meet the needs of endogenous fat oxidation.

    • Hemming  January 2, 2014

      Thanks Peter. I was simply thinking that the body at some point will hold on to the fat instead of oxidizing it.

    • Chris  January 3, 2014

      Peter has mentioned several times that a lean adult could have at least 40,000 kcals stored as fat in the body, that would be mobilized for oxidation. If your total energy expenditure/day would be somewhere at 2,500 kcal, this means that you could go up to 16 days relying only on your bodyfat, without anyother intake. However, I did not take consideration of metabolic changes that undergo when such situations are present, as well as mineral requirements.

      But I know I saw a documentary of a person who was able to survive for about a month trapped inside a cave having nothing to eat. I think it was on discovery few years ago.

    • Hemming  January 4, 2014

      My point was that despite that any person will always have some fat they might be able to oxidise it simply because the body will hold on to it. I would argue that at some point the body has to slow down its metabolic rate which would occur sooner when body fat is very low compared to a situation with normal body fat. I can assure you I’ve felt exhausted and hungry (not hypoglycemic) even after fasting for not more than 12h (being in ketosis) whereas many obese people report lots of energy and no hunger in much longer fasts.
      Your calculation would result in the person ending up with zero body fat. I’m not sure that’s viable. I’m not trying to be a wise guy. I’m just saying that in my experience ketosis is great for fasting etc. but at some point you have to eat again.

  2. Rs711  January 2, 2014

    Downloading it now! In the discussion, is the health vs performance aspect touched on or is this a solely performance-centered piece? Thanks (& nice to see you active in the social media scene)

  3. Edward  January 2, 2014

    I guess that it IS their podcast, but it sure would be nice if people like that didn’t interrupt constantly or feel the need to say “Oh wow!” or “Right” and so on. A respectful silence is beyond their comprehension, but that is the sign of a very good interviewer: let the guest speaker speak and then lead the direction of the interview with insightful questions that shows they have done their home work.

  4. Russell  January 2, 2014

    Excellent podcast. At what point in the fat adaptation range does ketosis occur?

    • Peter Attia  January 2, 2014

      I think it’s too confusing to think of it that way. Think of ketosis as the most extreme form of fat adaptation.

    • Russell  January 2, 2014

      That’s how I imagined it. I just wanted to be sure I wasn’t completely off base. Thanks for the feedback.

  5. Justin  January 2, 2014

    Just finished up Volek’s and Phinney’s Art/Science of Low Carb performance which is centered on athletic performance while being fat-adapted. From my own personal experience of being fat-adapted for about a year: I am generally able to perform and recover more consistently now consuming low-insulin response foods. However, I also do not get as derailed, bonking, etc while eating high-insulin response foods every once in a while. Looking forward to the next post about this.

  6. Jason  January 2, 2014

    Cool interview. I found it interesting about your example of the guy with the great fat burning rate but who is not in ketosis. I assume this means this is someone who naturally goes in and out of mild ketsosis.

    As an ultra runner and someone who went through the whole exercise of measuring ketones, etc it leaves me wondering what additional benefits to ketosis are vs. just being fat adapted. I enjoy the mental clarity and energy that comes with ketosis but even when my ketones are “low” I still feel that good. It is only when I dabble with significant carbs do I start to feel crappier.

    If someone is fat-adapted but not in ketosis, does this mean the brain is back to burning sugar for fuel rather than ketones ? What do you feel are the advantages of ketosis over being full fat adapted ? The line has been blurred for me a little 🙂


    • Peter Attia  January 2, 2014

      Possible, though in the case of this particular individual, he’s very well-conditioned (Cat 1) cyclist who consumes maybe 100 g/day of CHO — too much to make BHB, but certainly quite low relative to his “peers.” Your last question is an important one, which I can’t address right now. Too long for a short response.

  7. newbie  January 2, 2014

    Another informative dialogue, looking forward to your future blog post on fat adaptation vs ketosis .
    My question – I’m a doc like yourself, hoping to help patients with the limited knowledge that we have. Unfortunately, I don’t have access to the tests and markers which you describe, just the routine stuff.
    My question – I have patients like your wife (whom you describe as insulin sensitive) – these are women who are also lean and fit – without the markers of Met Synd by WHO criteria – ie, they have, for example, high HDL(>2), low TGs (eg 0.5), normal waist, low BP, low hsCRP(<0.5), but high normal FBS (6.0) and A1C (6.0%).
    I'm not sure if you know the answer, but maybe you can speculate, do these people fall into the insulin resistant lean group, who are at risk for metabolic consequences? Can you suggest resources that I can follow up to gain more information?
    FYI – I have started 2 of them on a diet to promote a fat adapted metabolism ( not nutritional ketosis) – lowish CHO (100 – 150 gm CHO) with higher fat and protein. Results are not impressive.

    • Peter Attia  January 3, 2014

      Hard to know without seeing everything. Anyone with elevated A1C and otherwise normal markers of IR, I tend to look for beta-thalesemia trait, which is easy to spot with small MCV on CBC. Also, helps to know apoE in some of these cases, but I realize you may not be able to get it tested “easily,” depending where you are.

  8. newbie  January 2, 2014

    Addendum -I don’t mean references for lean insulin resistance – I have that, I’m just not sure that the label applies. I am wondering if this constellation of results warrants any management, My searches have not yielded any results.
    Thanks for any time you may spend on this.

  9. Mark Williamson  January 2, 2014

    Peter – Hope you are having a great New Years. Thanks for posting the podcast and I was especially interested in the fact that the vitamin D reference population came from the Framingham study. Off the top of your head are you aware of any sources that provide the information for how various reference population data was collected?

    • Peter Attia  January 3, 2014

      LDL-C was also done in Framingham. LDL-P was done in MESA. But it’s interesting to ask (I don’t know the answer) where our references for things like WBC, or CRP, or A1C came from, other than “large” populations.

    • Mark Williamson  January 3, 2014

      Thanks for the additional info. This topic has been top of mind for me recently as we have been pulling together reference population data for a variety of biomarkers and behaviors and something interesting arose. Not surprisingly, A1c levels have been on the rise over the last decade, and the data in 2001/2002 shows that an A1c of 5.5% put a person in the 75th percentile, while in 2009/2010 a score of 5.5% places a person in the 50th percentile!

      This prompted two thoughts:
      1) It is incredible and scary that these markers are moving this far in UNDER 10 years
      2) I hope someone put thought into selecting reference populations because I would imagine that we probably have data from “healthier time periods” that we should use for certain biomarkers (e.g. – A1c)

    • Peter Attia  January 3, 2014

      To thought #1 — YES!
      To thought #2 — not a chance.

  10. steve  January 2, 2014

    Happy new year to you and best wishes!
    Excellent podcast. My take away: Fat adaptation is different for each of us in terms of how low we have to go on the carb scale depending upon how insulin sensitive or insensitive we are
    Also, not so easy to determine one’s insulin sensitivity. Am i interpreting this correctly?To what degree our the standard measurements of IR that you discussed in the podcast accurate? For ex, if someone was negative on all five markers could they still be IR, and would it be meaningful?

    • Peter Attia  January 3, 2014

      Yes, your interpretation is correct, Steve. The likelihood of being IR with zero signs of MetSyn is low, but not zero. The gold standard is probably one of the two cumbersome IV tests for glucose disposal, the “euglycemic clamp” and the “insulin suppression test.” I’ll write about these some time soon I hope.

  11. newbie  January 3, 2014

    Thanks Peter, normal OGTT, no hemoglobinopathies or reason to suspect prolonged RBC lifespan.
    I will see if I can access an insulin suppression test – maybe one of our endocrines will agree.
    I have checked fasting (16 hours) insulin, which was very low in one, and unmeasurably low in the other.
    Thanks again.

  12. Leslie  January 3, 2014

    I am a 63-year-old female, 150 lbs, and wonder if you could help me with a definition. In my youth – it’s been happening pretty much all my life – we (others, mainly female, relate similar episodes) called it “low blood sugar” or “hypoglycemia” but when I experience this I do not have low blood sugar (last time it happened I had a blood glucose of 127). I am not diabetic and am otherwise healthy. I believe it is a variation of “bonking” but this can happen when I don’t eat, or don’t eat the right kinds of things and is not related to exercise. I liked your example of the gasoline tanker that could run out of fuel – is what it feels like – weak, shaky, brain fog and generally feeling crappy and eating does not immediately rectify it. It rarely happens on the ketogenic diet, but I still want to know more about it. My only question is how can I search the literature on this when the term “hypoglycemia” is incorrect? I’ve tried searching “bonk” but that’s not very productive. Any ideas? Anyone else? Just looking for a name so I can accurately search. THANKS!

    • Peter Attia  January 3, 2014

      Historically, or maybe I should say traditionally, people have considered “bonking” to be a condition where glucose gets too low to provide sufficient energy for the brain. I don’t believe this is necessarily or completely correct. It may have more to do amino acids than it does glucose. I actually plan to write about this at some point.

    • Jason  January 3, 2014

      That is very interesting Dr Attia that you mention amino acids. Protein seems to be the one thing I keep going back to for long endurance events, I always feel ‘perked up’ after taking in some protein if I am dragging a little.

      When I take in glucose – nothing seems to change either way.

      Lately my 50 mile runs have just been on a couple of Quest bars or some amino acids tablets. I sometimes worry I am “burning” protein for fuel but the caloric content of the protein I take in is insignificant to the overall expenditure or that maybe I am stressing the body too much just completely relying on fat like that but I have not had any problems yet (recovery fine, etc). Stressing meaning maybe forcing my body to generate glucose from leftovers rather than ‘helping’ it out, etc.

      I would love to hear your bonking thoughts related to amino acids someday.


    • Peter Attia  January 4, 2014

      Yes, I look forward to writing about it.

    • Ash Simmonds  January 4, 2014

      Think of it kinda like caffeine (but not) – caffeine doesn’t provide energy directly, but it does stoke the fires.

    • Amy B.  January 7, 2014

      Hey Leslie,

      I’ve had something similar happen to me — all the signs/symptoms of low blood glucose, but when I checked, it was around 118. (Don’t remember the exact number…it was a while ago, but it was definitely over 100, so in theory, not “hypoglycemia.”) I have no citations to provide for this, but I remember reading somewhere that sometimes when we get those feelings that we typically associate with hypoglycemia, it’s not necessarily due to classically low blood glucose, but rather how far and how fast it fell from its previous high. So, for example, if your blood glucose *was* 225 and it falls rapidly to 120, you could potentially experience a false/pseudo low.

      This makes sense to me, but the part I’m most curious about would be why the BG would have gotten so high in the first place if I (and you) were following a low-carb diet. The highest I’ve seen mine in a long time was 170, and that was after drinking someone’s homemade grape kefir that obviously had a ton more sugar in it than I had assumed. I have no idea what mine was prior to the times I’ve experienced the pseudo-low, but I can’t imagine it was super-high.

    • Bob West  January 8, 2014

      Amy, I have heard the effect of a downward swing in blood sugar that you mention being called “reactive hypoglycemia.” Although this article does refer to the level also being low, at least one of the components of it is the rapid drop itself:


      I think that the sudden alteration may be the major factor in many cases.


  13. Simon  January 3, 2014

    Hi Peter

    I’ve been doing a lot of reading and research (out of my own interest) into low carb science and how it relates to someone like myself who takes part in triathlon events which is how I found this excellent blog.
    I just recently received a first print copy of a book written by a friends father, Rodney F Bilton (Professor Emeritus in Applied Biochemistry at Liverpool John Moores University, UK, http://www.biomedexperts.com/Profile.bme/121267/RF_Bilton) that is the result of his years of study into the effects of foods in DNA damage, cancer development and chronic disease. I thought I should bring his work to your attention as it sits alongside and augments recent literature I have read coming out of the US and indeed the information on this website, so well.
    I don’t want to sound like i’m trying to flog his book here (it’s only a small initial print available on eBay at the moment) but if your interested in contacting Rod drop me an email.

    For anyone who is interested…

    Keep up the good work
    Many thanks

  14. Sam Pearson  January 3, 2014

    Something that is causing me a bit of a headache is my understanding of the body’s response to fruit. I have read conflicting information that consuming sugar rich fruits such as bananas is bad and I can understand that from the sense of trying to achieve ketosis, however I have also read that fructose from fresh fruits doesn’t require insulin to be metabolised. If someone would like to keep their insulin response low (as I understand it, to prevent unwanted weight gain) yet still consume a source of carbohydrates for athletic reasons is fresh fruit a good safe source? My understanding has been confused between the 80/10/10 raw food community and the low carb community. I respect your scientific objective way of delivering information so wondered what your understanding is. Thanks, Sam.

    • Peter Attia  January 4, 2014

      Sam, you may find your answers in a few of the posts I’ve written about sugar and fructose. There are at least two, if not three, if I’m not mistaken.

    • Bob West  January 4, 2014


      In addition to Peter’s posts on fructose, it isn’t usually understood that many fruits contain glucose and sucrose in fairly high amounts. For instance, bananas have about the same amount of fructose (4.9 g/100 g) and glucose (5.0 g/100g), plus quite a bit of sucrose (“table sugar” — approx. equal glucose/fructose — 2.4 g/100g),

      Source: http://en.wikipedia.org/wiki/Fructose


  15. Jeff  January 3, 2014

    Hi Peter
    Just wondering if you read the book The Sports Gene, Inside the Science of Extraordinary Athletic Performance by David Epstien. Its pretty cool especially for an athlete.

    I’d like to know your thoughts on Vitamin D supplementation especially for athletes who live in far northern climates (it was -20 when I woke up this morning!). Generally speaking I have never noticed a difference, performance or otherwise, from when I took supplements and when I stopped. But I could see the case for vitamin D supplementation during the long dark winter months on the trainer.

    • Peter Attia  January 4, 2014

      I know the book, but have not read it. Read a review of it. Looks interesting. Vit D is one of the few vitamins I believe in supplementing (I don’t for some of the common ones like multi, or A, or C, or E).

    • Annlee  January 3, 2014

      It was a satire – sadly – which is apparent toward the end. Dang it.

  16. Martin  January 4, 2014

    Hello Peter,

    I]m really interested in Keto + Ultra Endurance and doing my experiments since 2010..

    Through experience I learned how important salt is. I friend of mine although doing expriments by sending sweat to laboratories ( if you like I can send you his contact). We found out how sodium requirements can vary for different persons and how it affects performance.

    But I ask myself how it could be naturally possible (without Boullion) to get enough sodium.
    I am doing paleo since a few years and do not really understand how you can get the high sodium without Boullion?

    Many thanks

    • Peter Attia  January 4, 2014

      Depends on the culture. Typically the blood of animals or salt in salty water were sufficient.

  17. Allen W.  January 4, 2014

    Dear Dr. Attia,
    Great podcast, miss seeing you on video while listening as you are an animated speaker and very expressive.

    Just wanted to say once again, thank you for all you do. Since I discovered your blog January 2013 and started following your lower carb advice I have lost 39 pounds (Saturday mornings are my weekly weigh in). I have reduced my Lasix to once a week and my Atenalol to 50% of the dose it was a year ago while maintaining a stable blood pressure. My Md thinks I am bad for not following his advice but can’t argue with the results.

    • Peter Attia  January 4, 2014

      Allen, thanks very much for your kind words, and more importantly for sharing this excited news for me and everyone else. Very happy to hear about your success and hopefully your doctor comes around and realizes there may be another tool in the toolbox.

  18. Ethan  January 6, 2014

    How much water do you drink in a day? Should your urine always be clear? Enlighten me Pete.

    • Peter Attia  January 6, 2014

      No evidence urine color corresponds to specific gravity, which is the metric we care about, so don’t worry about color. How much water I drink a day is probably irrelevant to you, though.

  19. Martin  January 6, 2014

    Peter, in the podcast you are saying that longer exposure to cold water, while long distance swimming, prior to adopting NK,might have contributed to your increased body fat storage. There are studies that support this hypothesis. On the other hand, there are many proponents of cold exposure who claim that it triggers thermogenesis and production of brown fat cells which should speed up beta oxidation of fatty acids. And there are some other people who suggest that cold exposure might even enhance the effects of ketosis.

    Do you have any thoughts on this topic?

    As a side note, ever since adopting NK myself, 1.5 years ago, I find it easier to exercise (running, cycling, hiking, climbing) but also normally function in colder temperatures.

    • Peter Attia  January 6, 2014

      I have zero thoughts on this topic and am not familiar with the research. If I immerse myself in an ice bath, which I do from time to time, it’s more likely because I want to reduce inflammation my muscles than triggering BAT.
      Also, not sure 12 hours in 60 degree water (marathon swimming) is remotely similar to 20 min in 40 degree water (ice bath).

    • Martin  January 7, 2014

      Thanks, I did not expect you to necessarily have any thoughts on this 😉 In fact I do appreciate that you are very reluctant to comment on stuff that you don’t have a high degree of confidence or understanding of. It’s not very common these days…

  20. Suzanne  January 6, 2014

    Hello Dr Attia, I’ve only just come across your blog, I’ve been reading with rapt attention as well as watching your video’s and listening to the podcast.
    Thank you! I’m finding all your material very interesting and informative.
    I intend to pay very close attention from now on:)

  21. Read  January 6, 2014

    This was interesting but I was truly moved by your TED talk and your comments on your reaction at the time to the overweight woman who required an amputation as a result of diabetic complications. I could see you were truly moved by what you have learned since and that you felt bad about your reaction at the time, after you realized it was not her fault so much as her ignorance, the lack of good science on nutrition, and perhaps bad advice. I think of you as a supremely rational person and so was surprised at the intensity of your feelings about this event. Perhaps I should not have been so surprised.

    It really set me to thinking about my own reactions to those who are grossly overweight, which secretly tend toward a lack of sympathy for those who “did it to themselves.” This is in spite of (or perhaps because of) my own struggles with weight issues which are now largely behind me. I now realize that my attitude was itself a product of ignorance and arrogance and so I am out of the business of blaming those who are overweight for their lack of self-discipline.

    Thank you for the insight Dr. Attia. I have learned a lot listening to you but I have never been taught a more valuable lesson.

    • Peter Attia  January 9, 2014

      Read, I also think of myself as a highly rational person who lives in a world of facts, so I was equally shocked by my response. I’m glad taht talk gave you some pause in your own interactions.

  22. Kathryn  January 7, 2014

    Great podcast. Your efforts at studying this topic (ketosis) are immensely helpful to those of us predisposed to metabolic disease, and especially to those of us who have children that are predisposed as well. Any thoughts on the best way to lose fat in ketois: cardio vs weight training or a combination of both? I’m a full time working mother who loves cycling but what I’ve read from John Kiefer and Dominic D’Agostino, I might be stalling my efforts at fat loss with cardio exercise (especially steady state cardio) and normally I’d be devoting my time to zone 2 heart rate training on my cycling training during this time of year.

    • Peter Attia  January 9, 2014

      A great question, but well beyond the scope of a quick response. I would suggest reading about high intensity training. I’m sure I’ll write about it eventually, but who knows when.

  23. Tee Dee  January 7, 2014

    Dear Peter,
    Thank you for another excellent article that helps to clear up many more misconceptions still being pushed by those who haven’t kept up with the research. I have a question that’s not really on topic, but I hope you won’t mind too much.
    I’m trying to get a straight answer from someone with your level of knowledge about health/nutrition: Would your diet be any different if you’d had your gallbladder removed? I had mine taken out in 1976 due to apparent multiple gall stones. It was about 8 months after my daughter was born, so I don’t know if my system was in a compromised state or not; nevertheless, it was removed. I was never told to do anything differently re: diet, but always wondered if I should have. My diet is pretty much identical to many in the paleo/low carb community, but I have added supplemental digestive enzymes and a probiotic to my routine just recently, hoping it would give me better digestion and gut health. Is there anything else you’d be doing to make up for the absence of a gallbladder, or is what I’m doing enough?
    I know you’re very busy with work and family, but I’d really appreciate any info you could provide.
    Thank you and here’s wishing you and your loved ones a very happy new year….

    • Peter Attia  January 9, 2014

      Probably not, but if symptoms (e.g., steatorrhea from inadequate bile discharge) dictated a change, of course, I would, such as increased meal frequency and reduced fat load in a given meal. Contrary to “popular” belief, the evidence that high fat diets cause gallstones is nearly nil. In fact, this recent review says otherwise: http://www.sciencedirect.com/science/article/pii/S1542356513018375

  24. Caitlin  January 8, 2014

    Hi Peter,

    Just a quick logistics question for you… do you think it matters if I eat bacon that’s cured in sugar? I don’t think it matters since it’s just absorbing the moisture out of the meat for preservative purposes, but I know about all the evils of sugar and I get a little suspicious sometimes…


  25. Maximilian  January 8, 2014

    Thank you for the podcast! I have a serious and funny question. I am now in ketosis for a week according to my urine test strips. Along the way I have noticed that my urine has turned more yellow and a bit darker, compared with the urine before (60% Carb-diet). In addition I am drinking more than usual at the moment (2.5 l per day), so I do not belive that it is dehydration.

    Of course urea-conc. might be high due to gluconeogenesis from amino acids and the urea/ornithine cycle (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/). But urea is colorless, isn’t it?

    Do you have any idea what causes the yellow urine? Did you observe the same phenomenon?

    Thank you very much in advance, Max!

    • Peter Attia  January 9, 2014

      Max, I don’t monitor my urine in any ways, so not able to comment. Perhaps others can.

    • Hemming  January 9, 2014

      I’m experiencing exactly the same but I can’t give you the biological reason for either.

    • Jeff Johnson  January 10, 2014

      T-Rex Takes A Pee

      This got me thinking – t-rex needs to take a leak – so he spots a Brontasuarus about one-hundred ft away and let one blast – dousing the Bronto –

      The Bronto gets mad as a giant 50 pound Hornet and walks over to T-rex and let’s loose with a thunderous tail smack – T-rex rols over and over after landing on his head about three hundred feet away –

      T-rex say’s to himself – da….m – that’s the last time I’m taking a leak on a Brontasuarus –

      Bronto say’s to himself – da….m – nothing beats a good tail whack

      Moral of this story – pay attention to who you pee on –

    • Steve  January 10, 2014

      This happens to me as well.

    • Amy B.  January 10, 2014

      Max — have you added in any B vitamins? Seems like your knowledge on this stuff is pretty advanced, but some people aren’t aware that some of the B vitamins can cause a darker urine. (Actually, maybe not darker…almost like fluorescent yellow!) It’s mostly the riboflavin, if I recall correctly. If you’re not taking any new vitamins, then I’m as stumped as you are.

  26. Dave  January 10, 2014

    Thanks for the link, since hearing your podcast with Vinnie and Anna I’m now hooked on their podcasts. I’ve also recently viewed your top 10 podcasts and your interview with the diet doctor. All very interesting and informative.

  27. Tee Dee  January 10, 2014

    Thank you for the feedback Dr. Attia; it’s much appreciated 🙂
    Theresa (Tee Dee)

  28. Stan  January 11, 2014

    Dr. Attia, has any testing been done for sufferers of emphysema, sever asthma and COPD in regards to a strict keto diet? It’s known that a ketone/fat diet requires less oxygen. Correct? Would this be a way to “trick” the body in having more available energy even with partial lung failure?

    Thanks for your great work!

    • Peter Attia  January 12, 2014

      Not that I’m aware of. I’d have to think about the impact of reduced VCO2.

    • Dr. Rob Janssen  March 7, 2015

      Before we all developed fat fobia, it was common practice to advise severe COPD patients a high-fat/low-carb diet. Fat as fuel produces 0.7 CO2 for every O2 and carb as fuel 1:1. In other words, by using fat as fuel you can reduce CO2 production by 30% which is significant for severely respiratory compromised COPD patients.

      Furthermore, I think there are more advantageous of a high-fat/low-carb diet for COPD patients. Ketones are suppressors of oxidative Stress (b-Hydroxybutyrate is an Endogenous Histone Deacetylase Inhibitor). Oxidative stress and inflammation are central in the pathogenesis of COPD. In contrast to what others claim ketosis does not lead to muscle waisting (which would be a concern in COPD patients). Finally, metabolic syndrome and COPD are correlated (perhaps because they share the same pathogenetic mechanism).

      I think there are plenty of reasons for a revival of the high-fat/low-carb diet in COPD patients. The only drawback I see is that COPD patients need extra calorie intake and this is difficult for them with a stomach full of fat which stays in there much longer than carbs and can make them more short of breath.

    • Peter Attia  March 8, 2015

      Yes, very good reminder for folks. Too bad more docs didn’t remember this point.

  29. Todd Williams  January 14, 2014

    Hi Dr. Attia,
    I’m worried that if I don’t go whole-hog with a low-carb diet and get into (and stay in) ketosis, I’m actually doing more harm by eating lots of fats and calories. Is there any truth to that? Thanks!

    • Peter Attia  January 14, 2014

      No simple answer to that complex question. Short answer is you definitely don’t need to be in ketosis to achieve benefit from CHO reduction.

    • Maryann  January 16, 2014

      Hi Todd, you might like to read Grain Brain by Dr. Perlmutter. It will explain in detail some of the benefits of low carb and healthy fats and why you might want to consider what they can do for your health. It is a great book, and Dr. Perlmutter cites Gary Taubes.

  30. Muath  January 16, 2014

    Thanks for the great blog. I am a big fan. I have a question that I had in my mind for a while.
    How does fat oxidation problems/disorders relate to the fat adaptation concept? Is there a test or a way to measure if there a fat utilization problem/disorder? Do different body muscles utilize fat with same efficiency?
    I am asking cause since I was diagnosed with type 2 diabetes a year ago (31 years old), I cut down carbs and got it under control. But my mid back muscles started hurting very very badly after taking statins for three months (then stopped) and am on physical therapy for a while now (no spine problems no nerve problems no elevation in cpk, just muscles). Sometimes, I feel that eating more carbs eases my pain and I have read that statins may miss up fat oxidation. Finally, looking forward to your cholestrol series chapter on Statins 🙂

    Thanks again.

    • Peter Attia  January 17, 2014

      Statins can cause muscle pain. You may consider asking your doctor to try different variants, until you get the side-effects under control. Eating carbs in large amounts and/or eating simple carbs will, as you note, interfere with fat oxidation.

  31. Indy M  January 17, 2014

    Dr. Attia –

    on the podcast you mention that for patients under your care, your evaluation examine several axis/dimensions(not sure I am saying this right). Question:

    Is GI track microbiome one of those axis/dimensions that you quantify, as part of your practice/patient care, by any chance?

    Thanks in advance!

    Indy M.

    • Peter Attia  January 17, 2014

      No, largely because I don’t think we have great tools to meaningfully quantify it. That said, I do make liberal use of strong pro-biotics, when necessary (e.g., post antibiotic cycle).

    • Indy M  January 18, 2014

      I had dental surgery in December and had to undergo antibiotic course before, during and after. I was quite worried that the antibiotics will alter my GI microbiome mix, maybe for the worse(I am Ketotic). So it would have been desirable to have a ‘before’ and ‘after’ picture of my microbiome, but as you say, those tools are not there quite yet.

      The microbiome mix did get altered a bit, from what I can tell, large dosages of pro-biotics notwithstanding. I am a little bummed out about that.

      Oh well. Thanks for the reply.

      Indy M.

    • Peter Attia  January 19, 2014

      Yes, that would be great. Larry Smarr has done the best job of this quantification of anyone I know.

    • Indy M  January 20, 2014

      “Can you coordinate the dance of your body’s 100 trillion microorganisms?”

      Thanks very much for the reference.

      Just watched the above video on TEDMED. There is hope!
      I will research what is out there as a product, next. I would like to map my 100 T micro guests! 🙂

      Indy M.

  32. Phillip Madonia  January 18, 2014

    Great TED presentation. Your hypothesis has much merit. We can look at families where everyone eats pretty much the same thing yet one child can be fat and another thin. Genetics for sure plays a roll but the food supply could be the linch pin.

    Please keep up the work.

    How can I help you in your efforts?

    Phillip Madonia M.D.

    • Peter Attia  January 19, 2014

      Thank you, Phillip. I’ve passed your info on to one of my NuSI colleagues.

  33. Bryan Lynch  January 20, 2014


    After reading Gary’s book, “Good Calories, Bad Calories”, as well as Jeff Volek & Stephen Finney’s “The Art & Science of Low Carbohydrate Living” I was sold on the idea of HFLC, which I commenced on Jan 1 of this year, along with a return to resistance training (@ 222 lbs/26.5% bf) After a period of 10 days in which I felt weak and saw resistance training results go down, I experienced a dramatic turnaround literally overnight, and have never felt better! In 20 days I have dropped 11 pounds of fat and added a couple of pounds of lean mass! So obviously, I am ecstatic about the results of living this way.

    But my question is about my athletic performance. I play volleyball as well, and find that, though I do have the requisite energy to “get through” the matches, I don’t seem to have the burst that I normally experience when I am reducing body fat & resistance training. Is this normal for early phase Ketogenic diets? I have consumed <30c@day for 20 straight days, and so I'm assuming I must be in ketosis. So, with the priorities in the following order:

    1. reduce body fat dramatically. (from 26.5% to 10-12%)
    2. muscular hypertrophy, (combine 1 & 2 for goal of best physique of my life at age of 38)
    3. athletic performance (mostly volleyball, basketball, & sprinting: want to see how much of my 18 yr old 38" vert leap I can recapture.)

    These are, by most of my friends and family's estimation, lofty and silly goals, but I am determined. My question is: given my objectives, is it likely that a more moderate, non-ketotic, LC diet would serve me better? I enjoy eating ketogenic & feel fabulous, I'm just curious if I could be helping myself more by NOT being in ketosis?


    • Peter Attia  January 22, 2014

      Hard to know from just this info, Bryan. Everyone responds differently, and sometimes (actually, often) an empirical approach is needed.

  34. Martin  January 21, 2014

    Peter, regarding the macronutrient composition of a ketogenic diet (as defined by Phinney & Volek): have you come across a situation that an adult who is physically very active (doing both endurance and power & strength sports) and generally healthy requires an even lower amount of protein than what Phinney & Volek recommend (1-1.5g / 1kg of lean body mass) in order to be consistantly >1mmol/l of BHB and maintain fat loss?

    I am referring to my own case here: with my reference body weight of 70kg (I am around 78 now so I am not that far away now, but for performance reasons i still want to go down), I’ve recently found that what lets me stay ketogenic and start losing body fat again, while maintaining full strength, endurance and mind clarity is the protein of level of <=50g/day (20-25g per meal, 2 meals a dayt) (which yields 0.71g/kg). Notice that I've been low carb for the past 4 years now (with the green salad being the only source of carbs, I initially went down from 85kg to 78-70 and stopped there) and started limiting my protein intake to <100g a day some 2 years ago when Art & Science of Low Carb Performance went out.

    Having followed the <50g day of protein for the past week, I am consistently around 1mmol/l of BHB, started losing fat again and feeling and performing great.

    Could my requirement for protein be that much lower?

    • Peter Attia  January 22, 2014

      Many times. People respond very differently to protein and CHO. The “rules” of NK are very high-level, at best. See the post about carbs and ketones co-existing as an extreme example. Need to consider activity, gene expression (time, genetics), and intake.

    • Martin  January 23, 2014


      As a side note: for me decision to go down with the protein to what I think is quite a low level was very tough mentally, much more so than going low-carbs years ago. I’ve made the decision after doing some more reading on the role of leucine concentration in the blood on triggering anabolic processes. Many nutrition experts claim that higher amount of protein per meal (>30g) is the key here but then Phinney & Volek make a point that leucine concentration naturally gets higher on low-carb, hight fat diet. Ergo, one can do with much less protein. I also realized that in the last 4 years (since going low-carb/paleo) I never had any injuries and my recovery time (for running/climbing) has been better than when I was 18. My goal now is to find the safe, lower boundary of protein intake.

  35. Laura  January 21, 2014

    My doctor believes ketosis will harm my liver and kidneys. He stayed that it’s dangerous for someone to remain in ketosis for longer than 2 weeks and urges me to consume 100g of carbs a day instead of 20g of carbs a day because low carb diets are unsustainable and harmful. This counteracts everything I have read. I’m not sure if I should provide him with information as to the safety of nutritional ketosis, or simply begin to search for another doctor. I know you can’t give medical advice, but it must be frustrating that so much of the medical community holds on to outdated ideas about nutrition.

    • Peter Attia  January 21, 2014

      It sure is frustrating that many doctors don’t understand biochemistry, physiology, or nutrition.

    • Boundless  January 22, 2014

      > My doctor believes ketosis will harm my liver and kidneys. He [said] that it’s
      > dangerous for someone to remain in ketosis for longer than 2 weeks and
      > urges me to consume 100g of carbs a day instead of 20g of carbs a day
      > because low carb diets are unsustainable and harmful.

      How does he explain the continuous existence of ketogenic cultures like the Inuit and Masai? You need a new doctor.

      For some observations on why far too many physicians are like yours, see:
      “What’s Up With My Doctor?” at

    • Sean  January 22, 2014

      At the same time, 100 grams per carbs per day is still fairly low when compared to the American average which is probably 300-400 grams. I would suggest that even just sticking to 100 grams per day would still be of benefit.

    • Nicola  January 23, 2014

      As stated by others, 100g/day of carbs is not that high anyway.
      Depending on your activity level, it will still allow mild ketosis.
      In my case, I am a runner, totaling over 300 Km/month, 10% of which over or around the anaerobic threshold, and what I have observed was that last December I averaged 193g of net carbs per day (I do not count fibers) and yet recorded an average of 0.34 mmol/l of ketone bodies in my blood measurements (measured every morning after overnight fast).
      And my QR at 70% VO2Max was 0.78, so pretty close to what is believed to be a fat-adapted state.

      So do not be obsesses by the 20-50g/day rule, check what is you personal level of carb tolerance, influenced by both your genes and your activity level, by trial and error. You already know that high-carb is not good for you, then start lowering your carb intake one step at a time, till you find your ideal level (which might take into account also some social aspects…)

    • Martin  January 23, 2014

      the question is: is consuming 100g of carbs a day sustainable? You would still be sugar-burning without a chance of getting ketogenic, you would still probably have cravings. It’s much easier to stay very low- than moderate-carb.

    • Sean  January 23, 2014

      Yes, that is a good point. I find that the more carbs I eat, the more I want to eat them. I take in between 50-60 grams of net carbs per day. Where I really run a risk is those times when I want to eat a high carb food and can justify consuming it because I am technically still staying under my 60 gram per day limit. Then I will take in 30-40 grams in one sitting- that is what messes me up, because then 3-4 hours later I just want more carbs.

    • Amy B.  January 24, 2014

      Laura, if you *do* decide to find another doctor, there are plenty who are well versed in ketosis, LC, and Paleo.

      Primal Docs: http://primaldocs.com/

      Low Carb Docs: http://lowcarbdoctors.blogspot.com/

      You *can* find medical professionals who will support your desire to continue with what others would consider an unconventional approach.

  36. terri  January 24, 2014

    I want to give my internist info in a respectful way and show her all this data She eats low carb herself and it took me 6 months to get an apnt with her. She is in her 50s and looks fit . do you have a format already for people to share with MDs? I have gone from 190lgs to 150 in the past 3 years. My A1C is now 5.2. I had gestational diabetes so I am so happy with that number. My MD says go 10 more pounds…I am 5’5″and 44. My total cholesterol has gone from 199 – 222- 268. I know that is normal b/c I am dropping fat. My HDL has gone from 59-76-89. My tric have gone from109-77-63. My ratio has gone from 3.4 to 2.9 to 3.0. My current LDL is 166. MD says she now wants me to follow the AHA diet b/c my LDL is high. She did not do a particle test. VLDL is 12.6. No way will I change my diet. I have been eating keto style and steadily upping my fat every year. I want to try to educate her and gain her help before I look for another MD. I take no meds, just supplements. I figure at 44 I should get a MD just for wellness. I read your whole site. I think she would be overwhelmed if I just give her your website. Thank you for any advice in how to gain her support.

    • Peter Attia  January 24, 2014

      All I’ve got is the blog and talks scattered around youtube.

    • Pam  January 24, 2014

      You could suggest reading “Cholesterol Clarity” by Jimmy Moore and Dr. Westman.

  37. Natja Ostruh  January 24, 2014

    Hello Peter!

    Is any connection between ketogenic diet and hair loss? I’ve read a lot about this on internet.

    Thank you

    • Peter Attia  January 24, 2014

      Not that I’m aware of. If it occurs probably worth looking at DHT levels.

    • Hemming  January 27, 2014

      I think it happens when people restrict calories too much. I’ve tried losing hair on a ketogenic diet but that was because of anorexia. I’ve seen several studies showing no effect on hormones etc. as long as people are eating sufficiently.

  38. Andre  January 24, 2014

    Peter, on the podcast you mentioned your wife: `life gets in the way, you have kids etc` – could you clarify that a bit? What diet were you guys on, was she on? Did she develop Cravings?
    There is not a lot of well controlled information on pregnancy, you find everything from ketones decreasing brain wight of mice embroys up to facilitates birth and evyerthing.

    Background: My wife is pregnant, we very ketogenic before, now only low-carb, we slipped away from the 1-2 meals a day to 3 meals a day and have low-sugar fruits (with tons of extra fiber / psyllium husk) almost every day now. We are still very low on carbs, have no sugar & starches whatsoever, but I doubt we are still in ketosis as much as before. We are both fine with it at the moment, not gaining and not losing weight, but I am fancying going back to full ketogenic mode (and hopefully ending her newly developed cravings).

    • Peter Attia  January 25, 2014

      I’m not aware of data evaluating the efficacy of ketosis in pregnancy. A low glycemic index, but not especially carb-restricted approach may be best for most. The more prone to gestational diabetes, the more carb restriction would help.

  39. Ken  January 27, 2014

    i have been following your “what i do eat from 2011? and cutting out all sugar, grains etc for like 4 months.
    got blood work recently and all of my metabolic panel was in the normal range except the ALT which was 65
    what is a good way of lowering my ATL? your thoughts?
    Also looking at the cholesterol whats your thoughts on the numbers specificly with the normal range triglicerices and the LDL number

    here is my testing for my metabolic panel and choleterol.
    Glucose 83
    Creatinine. mg/dL 0.9
    BUN 7 – 25 mg/dL 17
    Total Bilirubin mg/dL 0.7
    Total Protein g/dL 7.9
    AST U/L 35
    ALT U/L 65
    Albumin g/dl 4.9
    Alkaline Phosphatase U/L 60
    Calcium mg/dL 10.0
    Sodium mEq/L 137
    Potassium mEq/L 4.5
    Chloride mEQ/L 101
    Carbon Dioxide mEQ/L 27
    Glom Filt Rate, Est >59.5 mL/min/1.72 m^2 88.2

    Cholesterol, Total mg/dL 203
    TRIGLYCERIDE mg/dL 138
    HDL mg/dL 38
    LDL Calculated = 130 mg/dL
    Non HDL Chol. (LDL+VLDL) 165

    • wukang  January 28, 2014

      HDL 38? that sounds too low for a low carber.

    • Andre  February 1, 2014

      TG: your triglycerides are too high, looks like you are not doing low carb, try checking how much carbs you get or if you maybe have too much protein (increase fat then). it should be lower,
      have you been working out? are you losing weight or stable, or you overweight? that can have an impact here. if you are APO E4 saturated fats will bring LDL up as well. but forget about LDL.
      HDL: if you are overweight, do low-carb; exercise more and lose weight. if you are already on a LCHF diet you must reduce our caloric intake a little bit and/or workout more. on a very low carb diet HDL will increase over time (not much, maybe 20%) and triglycerides will naturally come down. you will never reach HDLs of
      forget about the LDL, your Triglycerides / HDL should be lower than 3.5, yours is above. if you live in the US get ox-LDL thats the most important one.
      ALT: mine took years to come down after i stopped with simple sugars etc, started working out and ended up doing ketogenic. what could work, working out, reducing alcohol & fructose, supplementing stuff like tumeric. that should give the liver some time to regen. check if supplementing NAC works for you. need to reduce liver load.
      get CRP done at least for inflammation.

    • Andre  February 2, 2014

      I forgot about curcumin, this has an effect on ALT, check out studies out there.

    • ken  February 3, 2014

      i am thinking i eat way too much protein. i need to figure out what amount i can have and also when i am told add more fats, how much is more? like adding teaspoons/tablespoons of oils? add more butter?. i need like some ways to know how much fat / protein combinations? anyone have a good way of doing this?

  40. Evan Jay  January 28, 2014

    Hey Dr. Attia,

    Just got my first NMR Lipid Panel results… LDL-P 2113. Any new data on ketogenic diets and elevated LDL-P numbers that you’ve come across? All my other numbers are normal. Interested to seeing how it changes in 3 months when I go back for another test considering I didn’t have a baseline, but looking for ways to lower this elevated particle number in the meantime, any tips/pointers?


  41. Indy M  January 29, 2014

    Nutrition expert Angela Lemond explained to Yahoo Shine, that high protein diets produce chemicals called ketones, which promote weight loss but can lead to kidney failure. “We recommend staying above 100 grams of carbohydrates per day to avoid going into ketosis,” she said and added, “We know people cannot sustain this way of eating and therefore, they re-gain the weight.


    I am not sure that is correct. Experts do not give any citations!

    Indy M.

    • Peter Attia  January 29, 2014

      Glad the experts are chiming in!

    • Martin  January 29, 2014

      Very incorrect. At least she heard something about ketones.

      The problem is that the message is still negative.

      Perhaps in the next 10 years..

    • Indy M  January 30, 2014

      I have been in Ketosis for about an Year now. In the beginning, higher than needed Protein was actually delaying my getting into Ketosis. Using Jenny Ruhl’s formulae, which gives very similar results as Dr. Attias’s rule of thumb, I found out that me, not a big meat eater, fish mostly, nevertheless was consuming twice as much Protein as needed for maintenance etc…Average American may be eating 2 to 3 times more Protein than what is required. The excess will be turned to Glucose/Glycogen is my understanding, hence the delay in going Ketotic. That amount of needed Protein, I must say, was lot less than what I imagined going in!

      So this experiment where one of the MD bro’s is consuming a ‘high Protein’ diet, is not making sense, in the face of it!

      Indy M.

  42. Norm  January 29, 2014

    That documentary is going to be on bbc 2 here in uk tonight. Looking forward to laughing at the usual nonsense and wrong conclusions. By the way, the guy on non sugar diet lost more weight…

  43. Norm  January 30, 2014

    Here is the link to the sugar vs fat:


    As expected, wrong science and wrong conclusions. “If the gold rusts, what the iron will do?”

  44. DonnaS  January 30, 2014

    I just read an interesting little sideline in recent news. Not sure where this belongs here……. According to what I read researchers at Emory have stated that “Kids who are obese by the time they start kindergarten are likely to stay that way through childhood and into adulthood.” I read that with interest because my obesity started at that age and has been a battle ever since even with dieting (including low carb) and exercise for over 50 years. Of course the recommendations are to get the kids on a healthy diet (got news for ya. Even a healthy diet cannot always stem obesity) and more exercise plus limit TV. The usual standbys for curbing obesity. May work, may not work. What gripes me is that they are not considering that maybe something happens hormonally at this age (around 5) that causes some children to become obese. They blame food intake. Well if the body is not getting what it needs because there is a breakdown in the system then the body is going to demand more food to try and get what it needs. The overeating is not the problem. It is the result of some type of breakdown in the human body that regulates fat intake, fat usage, whatever would be the proper term to describe it. I’m all for the healthy diet but I wish that medical researchers would look first to the underlying issues rather than resort to old standbys which don’t work in the long run if the system isn’t working properly. And quit blaming obesity on emotional issues. There are those who would disagree with me over this but I have long since concluded that my go around with obesity has nothing to do with emotional eating being the root cause. It is a medical, nutritional issue first and foremost.
    And as people have stated their frustration above in just how can they work with their doctor when the doctor claims ketosis is dangerous, I get frustrated too when I tell my doctor I have been obese for more than 50 years and have done this and that throughout all those years to lose weight (including expensive programs) that have worked short term but not long term to be told after explaining all of this to him that I just need to diet. Ah the frustration………. I am a reasonably intelligent adult that has a significant medical issue which impacts my life and of which I am very much aware but the moral righteousness that doctors bring to the issue of weight make it difficult to even discuss the issue with calmness and clarity.
    And to think what this moral righteousness can do to a young child. Obese young children are treated as if they have created this ‘problem’. And just how would a 5 year old do that when parents have more say in what they eat at that age then when they are school age. How about looking at the problem from a real medical standpoint to try and discover why the food intake does not become usable energy in these children. What is the breakdown?
    Whoops. I’ve gone on long enough. Thanks for letting me have my say.

  45. Michael C  January 31, 2014

    Hi Peter. I saw your TED talk and I think you would be very interested in the work of a veterinarian and naturopath who has a lot of important information on the role of minerals in effecting insulin and blood sugar.
    If you email me at poweroflife @@@ fastmail.fm I can send you an overview. I think you will find it to be a major missing piece of the puzzle, and very “practical and safe”.

  46. Arjun  February 2, 2014

    Had the same comment as Norm. A well wisher is trying to dissuade me from the low carb, high fat path. I have reversed most of the symptoms of metabolic syndrome – lowered BP and TG significantly, waist size by 3 inches. Increased HDL and feeling great. Thanks to you and Gary Taubes! It would be very interesting to see your comments to the Fat and Sugar documentary on BBC.

  47. Greg  February 17, 2014

    Impressive site, taking it all in. New to low carb, 2 weeks in, lost 12 lbs, not much else to report, but feeling exhausted, ketosis flu maybe. But I’m not stopping, full steam ahead. To my question; I was an ultra runner and all around physical fitness and adventure geek, then at age 42 the bottom fell out, inability to recover, chronic exhaustion, non-restorative sleep. Now I’m 54, it ain’t no life, severely marginalized. But it’s never stolen my spirit, self experimenter extraordinaire, Drs hate to see me coming, stearing and driving this on my own. I can’t exercise or exert without exacerbating all my symptoms and there’s a laundry list of them, exhaustion sets in 12-24 hrs later, lasts for days or weeks. The underlying sensation is this inability to recover, I always feel like I’m bonking but never recovering, never fully or even partially restored, no amount of rest, relax, naps, or sleep helps. I’ve asked everyone, what is it exactly that gets us recovered, what is the recovery system, where is the reset button? Never an answer.

    But now I read your site and I’m thinking bingo? After 2 weeks on <50 gm of carbs and copious gobs of fat, medium protein, I can safely say I was previously a carb glutton. I've just reviewed 10 years of blood results and there is a case for being near/kinda on the edge of metabolic syndrome, but not full blown. But 50 lbs of weight gain, high BP, high cholesterol has been constant, and an inability to reduces these numbers with numerous attempts. What do you think is the key to my recovery? Any advice is greatly appreciated, help an old guy find some light in all this darkness.


    • Peter Attia  February 17, 2014

      The other thing that is likely going on is hormonal imbalance (thyroid, adrenal, androgen). Best to find a good doc to augment your diet.

  48. Helen Stoddard  February 20, 2014

    Hi Peter,
    Thanks for posting the link to the podcast. I really enjoyed listening to it. Every time I read/listen to something of yours a new Aha Moment happens! This time the concept that a person can be quite well-fat adapted, metabolically speaking, whilst not necessarily needing to be in full-blown ketosis? Nice news for an all-or-nothing type of personality. I am finding bullet proof coffee and a hard boiled egg is all I need to easily last a 3 hour road ride, with just water for hydration. And, like so many others report, day to day I function so much better on less carbs, more fat and eat far less volume, less often than I used to. Profound thanks for all that you do and kindest regards.

    • Peter Attia  February 22, 2014

      Well, I’m definitely glad that point came across. It worries me when folks think “fat adaptation” and “ketosis” are synonymous.

  49. Dwight Morgan  February 26, 2014

    Hi Peter,
    I’ve enjoyed listening to your pod casts and YouTube clips.Have been reading Phinney and Volek’s, The Art and Science of Low Carbohydrate Living”. Here is my question: How is it possible to maintain a 1:1 (or nearly 1:1) ratio between the omega 6 and omega 3 fats in ones diet? All the nutritional charts I’ve looked at show most oily foods contain huge ratios of n6 to n3 fats. Nuts, peanut butter, coconut oil, olive oil, avocados, canola oil, eggs, etc. all have high ratios. One must have to eat lots of sardines and salmon! You’ve probably mentioned this topic before on this site, if so I apologize.

    • Peter Attia  February 26, 2014

      It’s pretty tough, but I’m not sure it’s necessary or even desirable.

  50. Dwight Morgan  February 27, 2014

    Another quick question:
    From Stephen Phinney and Jeff Volek’s “The Art and Science of Low Carbohydrate Living” book, this passage is on page 40: “We have done both human and animal studies examining the amounts of saturated fats in blood and tissue samples after a low fat, high carbohydrate diet versus a low carbohydrate diet containing appropriate fat. In both cases, the fat-containing diet provided about three times as much saturated fat. And yet, we saw no increase in saturated fat levels in either blood or tissue samples.” My question is, Were the humans and/or animals on the low carb, appropriate fat (with 3X the saturated fat) diet keto-adapted or not. The real reason for asking this is I’m concerned that while I am transitioning from a carb metabolism to a ketogenic state (duration 1-3 weeks), am I going to be vulnerable to damage from the extra saturated fats in my diet since I won’t be metabolizing them like I would if I were in a ketogenic state? Thanks in advance,

    • Peter Attia  February 27, 2014

      Great question, but I don’t know the answer. I suspect the answer may be different for different people, though.

  51. Karen  May 17, 2014

    Hello Peter:

    Thanks for posting the link to this podcast! Interesting and informative, particularly the discussion around hormones and the challenges of losing weight around peri-menopause and menopause. You mentioned the issue of whether declining levels of estrogen play a role. Some authorities on the topic (Dr Christiane Northrup being one) observe that a lot of peri- and menopausal symptoms, while routinely attributed to declining estrogen, may be equally (or more) likely to be attributable to estrogen dominance–hence the real issue, especially in peri-menopause, is declining progesterone. Even low-dose transdermal progesterone supplementation (in the form of over-the-counter skin cream) can counter estrogen dominance and provide symptom relief. (Presumably–or what I understand as a layperson–although oral doses of progesterone are much higher, the lower dose administered through the skin can be quite effective, in part because this route bypasses the liver….?)

    You did not have time in the podcast to go into a lot of detail re the question of estrogen and its effect on weight loss in women, but theoretically, I’m wondering if it makes sense that estrogen dominance could be a factor within the overall scheme….

    Thanks again for all your great posts!


    • Peter Attia  May 19, 2014

      Little doubt in my mind that estrogen plays a meaningful role in IR and associated changes (adiposity) in women (obviously), but also in men.

  52. Christopher  May 28, 2014

    Hello Dr. Attia,

    Thank you for all the work you put into this blog, both in regards to creating posts and giving feedback on comments. I believe you and your initiative might just be what is needed for us to start getting to grips with our ever increasing nutritional health problems. I wish you luck in all your endeavours.

    I have been having a go at NK myself for a month now, or two, if I was to count the time before my slip up during easter. But, I am having some problems and can´t seem to correct them, and I cannot really seem to find others that are experiencing quite the same difficulties while searching online. I am primarily interested in NK´s benefits in terms of athletic performance for sub threshold efforts.

    The problems I am having are related to my heart rate. It seems that my resting heart rate, which I measure when I awaken, seems to have risen almost 13 BPM from before NK. Exactly how many beat varies, but nevertheless it is quite a substantial leap around that mark.

    When I am exercising my heart rate has a tendency to be very high, even when my efforts are low. In comparison to a similar effort, but before NK, it is way higher. For example, when running, at a speed of 6min/km (very low effort) which should be at or less than 60%mhr it is now closer to 75%mhr. Add a tiny incline to that effor ant it might even reach 85%mhr. I find this very strange, especially because it never really feels like it´s that high. I have previously measured my lactate threshold for running to be at 88% and 62,3ml/kg, so I have a pretty good idea of what 85%mhr, and other values, should feel like. Of course, some days are better that other, some by a lot, but I have not been able to pinpoint whats causing this.

    I have been thinking that there might be some electrolytes that need balancing, but I have really been adding salt to my foods and drinking lots of bullion, and I have not really seen any improvement yet.

    1) Do you have any suggestions as to what might be going on here? Or perhaps any advice on how to “troubleshoot” something like this?

    2) Might it be time to get some bloodwork done? If so, any particular tests that are especially relevant for those in NK?

    Obviously – replies from others are very much welcome and appreciated as well.

    Thank you once again,


  53. sam  October 6, 2014

    Peter, this is a more general question about ketones. If one wants to create a glycogen deficit to enhance ketosis (or to prepare for a celebratory meal), is it better to do a shorter high intensity work-out, which I assume will tap into available liver glycogen quickly, or a longer, slower work-out. My current understanding is that the former would be more effective, but I note when you wrote about this in your blog, you reference taking a long bike ride to create a glucagon deficit.


    • sam  October 6, 2014

      Oops. Meant glycogen in the last sentence…

    • Peter Attia  October 6, 2014

      If you want the area under the curve to equal 10, is it better to have an area of 1 x 10 or 2 x 5 or 10 x 1?
      You need to put another constraint on your question for there to be a correct answer.

  54. Sam  October 6, 2014

    Ok, let’s say I only have 30 minutes for my workout. With this constraint, I assume a higher intensity workout would be more effective at reducing glycogen stores? Or did I miss your point?

  55. Sam  October 7, 2014

    Okay, so I found this on your blog “What do I eat, Part III.” I think this answers my question, unless you have some nuance to add…

    “I decided to go out for a glycogen-depleting workout (multiple sets of 3 min all out intervals on the bike) and about 36 hours later, after resuming my normal diet, I was right back into ketosis and felt just fine.”

  56. Khai  January 7, 2016

    I have started reading The Art and Science of Low carbohydrate performance by Dr. Volek and Dr. Phinney and they said to avoid alanine because it lowers post workout ketone production. My question is does this include beta-alanine which is found in most pre workout supplements and do BCAA’s have an effect of nutritional ketosis?

    • Peter Attia  January 10, 2016

      Probably not in small doses, but I don’t know. Also, gluconeogenic AA impact different people at different rates.

  57. Mark Stegemann  January 12, 2016

    Hi Dr. Attia,
    I found your work through the Tim Ferris podcasts and as a Type 1 diabetic, I was excited to jump in. I started a ketogenic diet YESTERDAY, and woke up this morning with a ketostick telling me I was already at 8mmol. It literally turned purple with the first drop. I’m curious if that’s because I injected almost no insulin yesterday (3units of Novalog/16units of Lantus) or because as a diabetic, I was already on a fairly carb restricted diet. Mostly, I’m unclear if there is a “perfect range” for ketones and if mine are too high already. Apologies if this is answered somewhere on your blog, I did my best to search. Thanks again for your work. I feel like it’s given me new hope.

    • Peter Attia  January 12, 2016

      You need to be very careful in ketosis with T1D. If you have complete beta-cell failure you will always need some insulin. Your doctor needs to be in the loop.

  58. Mylene  January 12, 2016

    Hi Peter,
    I’ve always wanted a healthy life, so after reading for 2 months about ketogenic diet I started. I wonder if I need a special care because it was removed my gallbladder 15 years ago. Do I have to avoid some kind of fats or take supplements ? I found very few information about it and I am sure many people as myself want to iniciate a keto diet but they have concern about this matter. I really appreciate your answer.

  59. Aaron  August 30, 2016

    That podcast doesn’t seem to be available any more. Is there good information out there somewhere on “this elusive concept of fat adaptation” (either from you or someone whom you respect)? Can it be described via resting respiratory quotient?

  60. Paula S.  November 21, 2016

    Struggling with LCHF – is there a workout recovery protocol? I can’t seem to find it anywhere. I always did shakes or a Vega sport drink but it’s pretty high carb. I feel really sick after a run if I don’t do anything and future performance, sleep and appetite really suffers. It feels like I have the flue, broth and electrolytes don’t seem to help.

    Age: 41, insulin resistant, slightly enlarged liver, can’t digest fructose or lactose, runs 30+ miles per week in addition to cross training (have kept that up now for ten years). I realize that’s not much compared to “real” runners but by day I’m an artist. I just really love running. Normally I could run 10+ miles fairly easily but not on LCHF, I doubt I could do a mile today. I’m bonked.


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