April 4, 2012


What do anabolic steroids, EPO, and carbohydrates have in common?

by Peter Attia

Read Time 8 minutes

Before getting to this week’s post, if anyone didn’t see the 60 Minutes segment on Sunday about the toxicity of sugar, here is a link to it.  I was pleasantly surprised by what they were able to convey with such time constraints.  In addition to the great work by Dr. Lustig, the very short segment showing Dr. Cantley, highlighting the role of insulin, insulin-like growth factor, and glucose in cancer, is a preview of what I’ll be writing about in the near future.

Back to the topic of the week: What do anabolic steroids, EPO, and carbohydrates have in common?  I know what you’re thinking…what is he talking about?  I’m going to attempt to make the following case today: carbohydrates do, in fact, enhance some aspects of human athletic performance.  So do anabolic steroids, human growth hormone (HGH), synthetic erythropoietin (EPO), and countless other drugs classified loosely and broadly as “performance enhancing drugs.”  The question is, or at least should be, Is it worth using these substances to enhance your athletic performance?

Before we go any further, though, I want to ask you to suspend one thought – ignore the “legality” of these substances.  For example, if we were going to have a discussion about cigarettes and marijuana, I would ask that we have the discussion based solely on their pharmacologic, physiologic, and pathologic features.  The legal issue is actually arbitrary and, frankly, highly illogical at times.  So, let’s take legality off the table.  Carbohydrates are legal and anabolic steroids are not.  Cigarettes and alcohol are legal and marijuana is not.  Understood, but irrelevant for this discussion.

Many people question the logic of reducing or outright eliminating carbohydrates, given the possible reduction in athletic and physical performance.  I’ve written about the impact nutritional ketosis has had on my physical performance, including here, and here.

For those of you not familiar with “standard” performance enhancing drugs, let me digress momentarily to explain what they are, how they enhance performance, and their associated risks (besides being stripped of medals or going to jail).


Anabolic steroids

This class of drugs, broadly speaking, includes a group of molecules that mimic the male sex hormones testosterone and dihydrotestosterone (DHT).  There is a reason, on average, that men have more strength and muscle mass than women, and these hormones play the predominant role in causing this difference.   Exogenous (i.e., supplementing whatever amounts the body naturally produces) use of these synthesized molecules leads to an increase in muscular strength and size when an individual – male or female – combines their use with suitable training.  In other words, taking anabolic steroids and playing video games does not increase your ability to run faster or lift more weight.  You still have to train hard.  However, anabolic steroids provide at least three significant advantages over doing it the “old fashioned way.”

  1. Using anabolic steroids allows you to recover much quicker, and therefore facilitates your ability to train harder than someone not using them.  The mechanism of this action is probably related to their ability to block inflammatory processes in your body.  Ever wonder why you hurt so much after a tough workout (or a long flight)?  Part of it is muscle tearing, which I’ll address in the next point.  Part of it, though, is your own immune system kicking up a fuss via an inflammatory cascade in an attempt to i) prevent you from causing more harm, and ii) repair the damage.  Blocking this process lets you feel better and workout longer and harder.
  2. Through their ability to directly signal at the level of the cell nucleus (steroid hormones go right into the cell nucleus and interact directly with DNA), anabolic steroids also directly increase protein assimilation into muscle tissue.  In other words, they increase anabolism – muscle building.
  3. Finally, anabolic steroids have been shown to decrease lipoprotein lipase (LPL) expression on adipose cells [Translation: anabolic steroids reduce the expression of an enzyme that sits on fat cells and “tells” them to store more fat].  Less LPL on fat cells = less body fat.

Taken together, these physiologic changes make you a leaner, more muscular, stronger person.

So what’s the catch? There is an enormous, and very contentious, body of work around the question of chronic toxicity associated with use of anabolic steroids.  I am not an expert in this, and I won’t pretend to be one.  I have read about it quite a bit and my take is that this field of study is shockingly parallel to that of nutrition, except with smaller sample sizes, worse science (if that’s possible), and even more involvement from Congress (it’s almost embarrassing how much Congress obsesses over this topic with public hearings relative to other problems in our society…but I digress).  If you want to see a fantastic (and highly factual) documentary on this topic, I’d recommend Bigger, Stronger, Faster*.

Chronic use of anabolic steroids is certainly associated with some undesirable consequences, such as increased blood pressure, dyslipidemia (especially reduced HDL-C concentration), acne, premature balding, erectile dysfunction, infertility, clitoral enlargement in women, and gynecomastia in men.

There is a lot of controversy around the psychiatric side-effects of anabolic steroids, especially with respect to depression leading to suicide and a condition commonly referred to as “roid rage.” Most data I have seen suggest anabolic steroids may amplify an already-existing condition but are unlikely to cause these symptoms.  Nevertheless, the side effects of using anabolic steroids are not negligible.

Anabolic steroids unquestionably enhance an athlete’s ability to do virtually anything that requires strength.  I can’t think of a sport where the use of anabolic steroids is not associated with a significant improvement in performance.  But this improvement comes at a cost.  The cost is, for most, dose-dependent (i.e., more use = more chance of side-effects), and certainly not always predictable.



Erythropoietin (EPO) is a hormone produced by the kidney which regulates the body’s production of red blood cells – the cells in our bloodstream that transport oxygen to all tissues and carbon dioxide back to the lungs.  Under normal circumstances the body highly regulates the concentration of red blood cells and hemoglobin. Hemoglobin is the protein carried by the red blood cells that actually binds oxygen and carbon dioxide and allows red blood cells to transport these gases in our bloodstream.  If you donate blood, for example, you are “giving away” red blood cells and hemoglobin.  Your kidneys, sensing this, make more EPO, which signals to your bone marrow to make more red blood cells and hemoglobin.

Blood doping, a practice carried out by athletes at a higher frequency until the development of synthetic (i.e., artificially produced) EPO, is the “messy” way of doing this.  An athlete would have about 10% of their blood drawn and stored a few months before competition.  In the ensuing period of time, their body would naturally produce EPO and return the hemoglobin level to normal.  Just prior to competition the athlete would re-inject their own previously removed red blood cells, giving them supra-normal levels of hemoglobin.  Today, synthetic administration of EPO gives the same result with less hassle.  There are subtle differences between these techniques, including how they are each detected in screening for the drug.

What are the benefits of using EPO?

If the average person walks around with a hemoglobin concentration of 13 to 15 g/dL, boosting that to, say, 17 or 18 g/dL provides a significant advantage in delivering oxygen to muscle cells and clearing carbon dioxide back to the lungs.  Any athlete whose performance is limited by oxygen carrying capacity (e.g., running, cycling, swimming, tennis, triathlon) will experience a great performance advantage using EPO.

The catch? There’s probably a teleological reason our bodies have evolved to regulate hemoglobin levels between about 13 and 15 g/dL.  Anything lower than that and we have less energy and deliver less oxygen to our muscles (though many people do live below this concentration).  But in a very non-linear way, as the concentration of hemoglobin rises above about 15 g/dL (which can occur naturally in a few disease states), the viscosity of blood increases, which directly increases the likelihood of blood clot formation.  In particular, increased blood viscosity is associated with an increased risk of myocardial infarction (heart attack), cerebrovascular thrombosis (stroke), and pulmonary embolism (blood clots in the lungs).  All of these conditions, obviously, can be fatal. While it’s unclear what percent of athletes who use EPO or blood dope suffer these adverse effects, it’s not zero.



Carbohydrates are one of the three macronutrients we consume (the others being protein and fat).  What makes carbohydrates unique is that our bodies can use them under anaerobic conditions.  This means that at levels of exertion so great that your body cannot get oxygen to cells quickly enough for oxidation (use of oxygen to fully harness the energy of fat or carbohydrate), you can still use a less efficient method to extract some energy.

It’s a bit more complicated, though.  You’ll recall from this post and this post, one can still carry out anaerobic activity without actually eating carbohydrates.  How? The quick answer is that consuming protein and fat, even without carbohydrates, generates sufficient substrate to produce glycogen, which is actually what our muscles use during these periods of cellular oxygen deprivation.  Do our muscles and liver contain as much glycogen without consuming carbohydrates?   Almost certainly not.  Are our muscles as efficient at utilizing glycogen in the absence of regular carbohydrate consumption?  Not in my experience.  In other words, eliminating carbohydrates from your diet can be detrimental to some aspects of your performance.  Stated yet another way, carbohydrates are a performance enhancing substance. 

I’m not going to spend any time discussing the “catch” (i.e., the drawback) with respect to carbohydrate consumption (e.g., insulin resistance, metabolic syndrome, obesity, diabetes, cancer, Alzheimer’s disease) since I devote this entire blog to that topic, so let’s revisit the original question.


What do anabolic steroids, EPO, and carbohydrates have in common?

For starters, they all enhance some aspect of your athletic and physical performance, depending on the activity you’re participating in.  Secondly, they all have variable efficacy depending on dosage and genetic/individual factors.  Finally, they all have side-effects, also dependent on dosage and genetic/individual factors.


Is it worth using performance enhancers?

Keeping legality out the discussion, (after all most of us are not Olympians subject to constant drug testing and regulations), should we use anabolic steroids, EPO, or carbohydrates to enhance our physical performance?

It depends.  Again, let’s keep legality out of it to normalize the discussion.  If your goal is to win the Tour de France, should you use EPO and some form of anabolic steroids?  It’s very hard to imagine how anyone, regardless of natural ability and training, could do what is expected of these athletes without some supplemental chemistry.

What if you want to be a starter in the NFL? Hit more home runs than anyone else? Set the world record in the 100-meter dash? I’m not saying you must use performance enhancing drugs to do these things, but it sure helps.  Furthermore, if anabolic steroids, EPO, and other performance enhancing drugs weren’t actually illegal, I’d be willing to bet their use would increase dramatically among both professionals and non-professionals.  [Non-professionals – i.e., “normal” folks like you and me – far outnumber professionals in the use of performance enhancing drugs, probably by over 10 to 1.]

I will pass no judgment on anyone who chooses to use anabolic steroids or EPO or carbohydrates to enhance their performance.  I will also pass no judgment on folks who use marijuana to ease their pain or to relax.   As I said earlier, I think the legality of these substances is arbitrary.  Cigarettes and alcohol are ok, but marijuana and anabolic steroids are not?

Everything has a tradeoff, which is exactly why I don’t like being asked, “Hey Doc, what should I be eating?”  How should I know?  It’s as illogical a question as, “Hey Doc, should I be using anabolic steroids?” If you are aspiring to win an Olympic medal (again, assuming all performance enhancers were legal), the answer is probably, “Of course you should…and while you’re at it, add some human growth hormone!

You want to win the NCAA championship in the 200 yard freestyle?  Ketosis is probably not for you.  Sure you can (and should!) restrict sugar, but I think you’d be better off consuming, say, 40% of your calories from rice and non-wheat, non-sugar starches.

So why am I in ketosis, even though I might “perform” better at some things if I ate carbohydrates?  Because I’m a 39-year-old wannabe athlete whose athletic performance is irrelevant.  Not a single person cares how fast I swim or ride my bike beyond myself.  I have no sponsors. I will never earn a paycheck for how fast I can flip tires or climb Mount Palomar.  I am more than willing to give up some athletic performance (e.g., sprint speed, peak power) in exchange for other athletic benefits (e.g., greater aerobic capacity and metabolic flexibility), especially when the real gain is greater health and a reduction in my risk for all diseases associated with metabolic syndrome (heart disease, diabetes, cancer, Alzheimer’s disease, and others).

Can I tell you what to eat, what to drink, what to smoke, or what to inject?  Perhaps, though I’m not sure how relevant it would be (or why you’d want to listen to me).  What I really want to do is at least give you a sense of how to think about the tradeoffs involved in each of these decisions so you are better able to make the right decision for yourself about what to inject or what to eat to enhance your performance.

By melvil (Own work) [CC BY-SA 4.0], via Wikimedia Commons

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  • Eric

    Great post Dr. Attia. Although not the main theme of the post, I like the points you make about how arbitrary substance legalization has historically been in the U.S. Just like our government’s food pyramid – unfounded both scientifically and logically but highly influenced by those who profit from mass production…

  • Birgit

    Very interesting perspective. I totally agree that the legality/illegality of substances is very arbitrary.
    Since I have never been competitive (other than with myself) I have never been tempted to use performance-enhancing drugs. In a sense their use is not so different from other behaviors that might enhance performance in the short run and negatively impact health in the long run. I minimize swimming because chlorine makes me feel bad (right away). But I may not always remember the long-term consequences on my joints when I run downhill or the injury risk when I ride my horse. When I look at overuse injuries in high-school kids (cross-country, football, boxing, even swimming) that are not just tolerated but encouraged by many coaches and parents I know that performance enhancing drugs are not the biggest, and definitely not the most common problem. Exercising for joy and health as Mark Sisson describes in his book is a value that is rarely supported in our society.
    I continue to be amazed how many people started running, biking or swimming to lose weight and be healthier and then later become so focused on performance that health become irrelevant to them. Even those that understand the effect of carbs may choose to ignore it.
    On that note, I can’t wait to hear more about “superstarch”. 🙂 I always thought of modified corn starch as something I should avoid. What is different about this?

    • Birgit, if I remember your time from that marathon last month, you don’t need any help!!!! Yes, I need to start writing about superstarch. So much to do…so little time. I’ll explain, at that time, the differences between argo starch, corn starch, amylopectin, and “superstarch.” I’ll try to make it worth the wait.

    • Birgit

      LOL, I wish it was a marathon, it was a half-marathon which took me close to 3 hours and my only excuse is that I had a bad cold that day and just dropped my carbs way down. 🙂
      Maybe I shouldn’t have said anything,ha,ha!
      So, I do need the help, but now that my net carbs are under 50 grams and I know I’m in ketosis I’ll start training Maffetone-style again and see what happens. Most of what I thought of as hypothyroid symptoms (I had a partial thyroidectomy and refused to take hormone replacement so far) are gone. I love having energy to exercise. I’m getting up to 2-4 hours of low-to moderate intensity exercise (running, hiking, horseback riding, ice skating, barn work) on some days and LOVING it. 🙂

  • Kathleen

    “As I said earlier, I think the legality of these substances is arbitrary. Cigarettes and alcohol are ok, but marijuana and anabolic steroids are not?”

    I totally agree with you. Personally, I do not much care for any of the above, apart from wine and spirits–which I mostly use in my cooking (I am such a lightweight).
    But, from what I have observed in others, these are victimless “crimes”. And the enforcement of these laws is very costly on a number of levels.
    I would sooner incriminate and prohibit cigarettes than marijuana. But really, I believe the cost/benefit analysis involved in using any of these things to be the prerogative of reasonable adults.
    Of critical importance is having the right information, as is the case with nutrition.
    Thank you for yet another informative and paradigm-busting post.

  • Dave

    Peter I have a question concerning hemoglobin, as I a male 52 yo, I constantly hear about iron being oxidative in vivo. I feel better when taking iron chelated with glycine, I am not short of breath after a gym workout or HIIT, recover easier, heart rate drops quickly after the intensive phase. However, when I get paranoid and skip iron G for a few weeks, I get fatigued upon exertion and short of breath. My blood work is normal in regard to hemocrit and RBCs. I have mentioned and been ignore by my doc as being in my head. Any idea on what may be going on… thanks

    • Dave, I’m not sure. Is there any way you could have a friend give you either iron or placebo (unbeknownst to you and him/her for a few months — say 1 month of each) and see if you can tell the difference? I used to this sort of stuff with myself when “testing” things out to see if I could really tell a difference.

    • Dave

      to the best of my knowledge there should be no placebo effect, as usually I just neglect to take it for a month or so, and the (sob) sneaks up on me, same with slow recovery. After awhile I take the Iron and the problems disappears within a few days. been going like this for a while.

      thanks Dave

  • Michele

    This may be off-topic, nevertheless, I will ask the question and see what Peter or anyone else has to say if this is of interest –

    Let me preface my question with the fact that I believe low-carbers/ketotic-eaters implicitly and explictly agree that this eating style is worth any tradeoffs present. However, I am interested to hear anyone’s opinion on the regulation of carbohydrates as once mentioned in a link Peter made to a CNN article discussing it…

    What do you all think? Should carbs* (*here I mean simple sugars, processed foods)be regulated at the goverment level? Or should we all be to make our own decisions based on the tradeoffs?

    • Michele, I have strong opinions about this, but I don’t want to bias the field. Love to hear what others think!

    • Please, no more government regulation and interference. We are drowning. How do you think we got where we are now, re: food pyramid, HFCS, etc

    • Eric

      It is really a question of one’s fundamental ideas of government’s role in society. Either you want the government to make decisions for you or you want to make and informed decision on your own. Regardless, the federal government should at least inform the people of the health risks based on the available (good) research, as it has with tobacco and alcohol – right on the label of every product.

    • Kathleen

      “What do you all think? Should carbs* (*here I mean simple sugars, processed foods)be regulated at the goverment level? Or should we all be to make our own decisions based on the tradeoffs?”

      I realize it can be tempting to want to regulate something that so many people (either knowingly or unknowingly) harm themselves and their children with. But it is much easier to install regulations than to abolish them, even when it is clear that the regulations are largely ineffective and/or harmful. Who among us could not easily lay our hands on recreational drugs or steroids if we wanted them?
      There is no perfect system. But having access to reliable information, based on properly conducted and interpreted research, goes much further IMHO (no small task!).
      Having access to assistance and support if one makes what turns out to be the wrong decision for them is also important.
      Having said that, I can see reasonable exceptions for things like school lunche programs and WIC

    • Edmund Brown

      I think the track record of food regulation at the Federal level is so poor I don’t want the Gov to have anything to do with it. I’m in favor of states taxing simple sugars and junk food to incentivize better eating behaviors, to level the playing field a bit between junk and good stuff, but I don’t want macro-nutrients, micro-nutrients, or any foods to be illegal.

      I think there’s a pretty substantial corpus of work that demonstrates that the majority of people (80% or so) are negatively affected by wheat, irrespective of the carb content. But that doesn’t mean I want to see all wheat products banned. I’d rather work the education and trial front. If people are informed and willing to try a month gluten-free they can figure out for themselves if they want to eat the stuff.

    • Birgit

      Most people who want government regulations don’t believe they need these themselves but that other people (who they perceive as less educated or able in some way) need these regulations. I grew up in a country, Germany, where the government made a lot more rules, in particular about health care, for individuals and while it guaranteed decent (much more than minimal) care for everybody it did nothing to encourage healthy lifestyles and truly preventative health care. Therefore I advocate keeping the role of government relatively low but protecting children much better who can not make informed decisions (mandatory health insurance, education, high quality P.E., high-quality school lunches) and whose parents to a poor job.
      Right now the government is doing a lousy job at that, one reason we home-school our daughter. She gets to eat low-carb organic and execises at least two hours most days.

    • Debbie

      I don’t think any food, real or fake, should be regulated, or even come with a warning label; but I don’t think food stamps ought to be redeemable for anything other than real food – and that would include carbohydrate, so there would be someone making lists of which carbs were food and which weren’t: bread = food, Soda = not a food, etc. This gets into politics too, but I don’t think it should. And it’s not an ideal solution, but I think would do some good for some people.

      I also think giving some kind of tax credit to those who raise healthy cattle and other animals for slaughter would be good. In other words, don’t demonize, but, rather accentuate the positive. Something like that.

    • Michele

      Thanks, everyone, for being so kind and commenting. The general consensus that I’m reading from these comments is that the “solution” (if there is truly a solution) lies in information, not regulation. Even though I tend to think regulation is good, I very much agree with informing people over dictating to them…

      @Birgit, am an expatriate living in your home country, Germany. I don’t feel like people (Germans AND foreigners) here are fat-phobic like in the US, nevertheless, I’m seeing more and more morbidly obese people which is heartbreaking.

  • Tony RiccI

    Excellent insight, analogies, and perfectly addressed are the most relevant questions and considerations for developing individualized dietary practices.

    Tony Ricci, MS, FISSN, CDN, CNS, CSCS

    • Tony, if I got any of it wrong, I know you can correct it! Thanks so much.

  • Bobby

    Peter: Maybe no macronutrient is safe. I have read numerous studies showing that even a short term high fat diet has negative effects on the cardiovascular system and causes inflammation. See http://www.sciencedaily.com/releases/2012/04/120403112004.htm#.T3ww9Klltds.email
    for example.
    My concern is that a high fat diet might have some positive short term effects but some very negative long term consequences. Clearly, we are all different, and maybe some folks may be fine just like some folks seem to do well on a high carb diet. I guess in the end we must all just self experiment to find what works best for us–or at least what we perceives works best.

    • Bobby, this study is not something you should look at to get any sense of the long-term (or short-term) benefit of fat intake. Why? Because it’s done in mice! I hope everyone reads this. PLEASE. Mice studies are irrelevant when it comes to nutrition. They are, and have been forever, herbivores. They did not evolve like we did. If I did a study that tested the impact of cats on mice health, what would I find? I’d find that cats negatively impact the health of mice. Would it be fair or correct to extrapolate this finding to humans? Of course not! I’m not picking on you, so please don’t take it that way. But I get 10 emails like this a week. I want people to really understand the limitations of these silly mice-nutrition studies. They should not be done, and when they are done, the reporters who write about it should be smart enough to know better. Clearly I’m expecting too much…

    • Bobby

      My feelings are not hurt because I recognize the weakness in nice studies. Still I wonder if we have any long term studies with humans that we can rely on to know the long term safety of such diet? Might eating a high fat diet come back to haunt us just like eating a high carb diet? Might it vary among the population?

      • Bobby, was that a Freudian slip? (nice studies… ’cause I think they are anything BUT nice!). The best we can do, besides the obvious (i.e., we evolved in a world with predominently fat and protein — very little carbs — and the few carbs that we did eat looked nothing like the ones we eat today), is ask the question, ‘What short-term measurements can we make that proxy for life-long change?’ Good news is lots! We know what low HDL-C, high LDL-P, high blood glucose, high insulin, high CRP, high triglycerides lead to —>> metabolic syndrome and early death. We know eating all the fat the world, when you strip out the carbs, improves every single one of these metrics. Ergo…

    • Jon

      “Male mice (8–10 weeks; C57Bl/6) were purchased from Taconic and used according to the University of Virginia Animal Care and Use Committee guidelines. Mice were separated in two groups: a control group, fed with a normal diet (3.1 kcal/g, 0% cholesterol, 5.8% fat, Harlan Laboratories) and a second group where mice were fed with a caloric-rich diet (5.45 kcal/g, 0.2% cholesterol, 35.5% fat; Bio-Serv) for 6 weeks.”

      Without delving too deep into this, it is unclear to me whether the mice were also significantly carb-restricted, or if they simply just had a greater percentage of fat in this “caloric-rich diet.” If you keep eating the same amount of carbs, and just increase the amount of fat, you wouldn’t expect to see a positive benefit to simply eating more, with more of it being fat. I am assuming that if you, Peter, were NOT in ketosis, and instead ate say, 150g of carbs a day or 200g rather than 40-50g, that you wouldn’t expect to see the improvements to your disease risk factors that you do if you still ate as much fat as you do, correct?

      • Correct. If I were consuming normal amounts of carbs, especially sugars, the amounts of fat I consumed would not be effectively mobilized and oxidized. Great job pointing this out, Jon. This is a constantly recurring weakness of many of these studies, especially in humans.

    • KevinF

      Bottom line, we don’t need the mousetrap. The cheese by itself will give ’em a heart attack.

    • Bobby

      Just dyslectic. My bad. Freud can’t claim credit for it. Bobby

  • David

    I spike my carb intake just two days per week (after work out). Otherwise, < 100 grams per day. When I do the post-workout carb fest, it's usually yams with butter or beans. And I've noticed over the past few months of doing this that these are same two nights that I sleep the best (other nights, just okay sleep, but not real deep or long). Is it the intense work out that sends me into a deep sleep, or the higher carb intake? Not sure.

    • Great question, David. You know how to find out….try the experiment of crossing the two variables.

  • Claudia

    Another great post, as usual. I was wondering if there is any evidence of the reversal of the negative effects/risk factors of high-carb eating once in ketosis or on a LCHF diet (ignoring genetic predisposition)? I suppose it depends on each risk factor: diabetes, heart disease-yes, Alzheimer’s disease-maybe?

    • Enormous evidence. In fact most people with type 2 diabetes who require insulin can be off insulin completely within 8 weeks and free of diabetes within another 2 months. Look at the work by Hussein Dashti who has done great work on this. Beyond these dramatic examples (I’ve seen countless with my one eyes, also, thought not published), look at the A TO Z trial. HDL-C goes up, TG goes down, insulin resistance abates, etc. This is the GOOD news! You can fix it. If you want one more example, look my personal journey section on the blog that chronicles my change.

    • Claudia

      Many thanks. Just read Dashti here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/
      I don’t get it: With this kind of evidence, why hasn’t it been embraced? It’s mindboggling.
      Know of any enlightened docs here in Italy?
      My in-laws are a hard sell.

      • So glad you looked him up. He has authored countless papers on this in many types of patients (e.g., obese, diabetics). You ask a great question. Between this work, the work of Steve Phinney and Jeff Volek, Christopher Gardner’s “A TO Z” Trial…how is low-carb still do demonized by the mainstream? It’s a real cognitive hurdle for people to go from where they are.

    • Claudia

      Got “The Art and Science” http://www.amazon.com/Art-Science-Low-Carbohydrate-Living/dp/0983490708/waroninsu-20 in the mail this week. Lots of homework. (I started with GT’s books). Next step is Marketing. I’ve been a fan of the Heath bros “Made to Stick” for some time. My favorite anecdote in that book was about the guys in Australia who ingested the ulcer bacteria http://en.wikipedia.org/wiki/Helicobacter_pylori to prove to stubborn medical community that these ulcers were caused by bacteria. Talk about experiments of n=1! Got a Nobel Prize, btw.

      • What they did, beyond the self-experiment, is a great example of what I’m hoping NuSI can be a part of — over a decade, introduce enough good science to actually change a medical practice 180 degrees.

    • Claudia

      Totally agree. And I think most of us on this blog are not only pulling for you and NuSI, but more than willing to help “keep the discussion going between posts” as you say below.
      So I think my t-shirt will say “I’m ketonic – 3.1!”

  • Guy T.

    >> What I really want to do is at least give you a sense of how to think about the tradeoffs involved in each of these decisions so you are better able to make the right decision for yourself

    Can’t ask for more than that. Good post!

  • Excellent post! I spend much of my time explaining to clients why I carry carbohydrate powders since I recommend and adhere to a low-carb lifestyle. I train Olympic sprinters as well as other athletes who use carbohydrate powders.
    I will definitely use this post as a source of reference.

  • Barbara Hvilivitzky

    I agree, your last few paragraphs for ME have the most value in this post.

    I’m becoming increasingly convinced that staying in ketosis is the way to go for ME. The new stuff coming out regarding protection against cancer, Alzheimer’s and other dementias is very encouraging. As well, leanness as opposed to fatness, and just feeling light and generally good makes sense. One can’t eat everything! As Mr. Taubes says there has to be something sacrificed – question is: what? To me the carbohydrates have to go.

    Peter, I frankly am not interested in all the complex stuff about athletes and their testing, performance numbers and the science behind it all…but when you wrap it all up at the end as you’ve done it makes sense for us all. Once again you’ve nailed it…thanks!!

  • David Nelsen

    Life is definitely about tradeoffs. In some cases the sport governing bodies have to save people from themselves. Look at baseball during the steroid era. I’m not eating low carb because I hate carbs. I’m eating it to lose weight, feel better and improve heart health. I still see all my favorite carbs in the stores and those trigger memories, but I’ve finally gotten to the point where the bigger goals I have far outweigh the joy of eating them. I understand why athletes on the cusp of stardom use banned substances and also guys who’ve been on top and see themselves slipping. I think the negative side effects of using EPO and steroids are evident much sooner than the effects of carbs, but all three take their toll in the long run.

  • tess

    lol — why i’d want to *listen to you* is that you’re NOT giving me a blanket dictation of what i should eat…. bravo, i admire your attitude!

  • Hard core 46 year old mountain biker here and even though I suck, I still do my best to improve. A couple of months ago I rigorously began to avoid carbs and ditched diet sodas as well. I haven’t checked with a blood monitor but I figure I’m running on ketones. I’m down roughly 10 pounds in that time and my mountain biking has improved dramatically. As a Clydesdale (6’3″ – 200 lbs), climbing has always been my weak spot and that has been the area where I’ve seen the gains lately. I was very interested when I saw your article showing how you are more efficiently using fat for energy and I think that’s what’s caused the improvement in my climbing. Purely anecdotal I know so who knows what’s really going on but whatever it is, I like it.

    • Keep up the good work. At 170 pounds, I’m also a Clydesdale on the road bike next to the 140 pounders who whiz by me…but at least I can squat more, do more pull-ups, and swim faster, right? I’m sure you can too!

  • Kristen

    I wasn’t expecting the point to your article from the title, but I much appreciate your take on the importance of understanding trade-offs when we take in anything into our bodies. Learning about low-carb eating (and thereby learning about nutrition, supplements and drugs along the way) has been so instructive in my being in charge of my body, instead of feeling at odds with it or as a victim of outside forces (fad diets, fad anything). Thanks!

    • Love when I can take a boring title and make it worth the read! Thanks for your patience. Of course, a *good* writer can do the opposite — they can create a title so broadly appealing that everyone wants to read the post.

  • lorraine

    Very cool way to continue the message that threads throughout this blog, that everybody has to figure out what works for them and be willing to do that n=1 experiment.

    Bigger, Stronger, Faster* is available on Top Documentary Films for free. It’s really worth the watch


    • I think I’ve watched this 3 or 4 times. Really worth the time (saying a lot from a guys who watches 2 hours of TV a month).

  • Janet

    I always look forward to your posts and this one did not disappoint. Thank you.

  • Geoff

    Your posts on the benefits of ketosis have been way helpful. If all goes according to plan, I’ll be there by July.

    I don’t see much out there on the link between ketosis and depression. My wife has it, and is taking an SSRI. Any reason to believe ketosis would help her?

    • I am not familiar with it, but only because I have not looked. I’m not sure it’s been studied, but like the discussion on ADD/ADHD, an N=1 experiment is an idea to at least find out of the impact in your wife? Depression is pretty complex and I’m not a neurobiologist, so I don’t even have enough “basic” knowledge off the top of my head to comment on the interaction of glucose with, say, serotonin.

    • Birgit

      have your read “Wheatbelly” by William Davis. There is some indication that wheat causes damage to different parts of the brain, maybe including those that regulate emotion, and not just for people with symptoms of celiac and/or gluten-intolerance. Also, many people, myself included report having much increased energy levels when reducing carbs and I know that chronically low energy levels can leave one feeling quite depressed after a while, especially since it often limits outdoor time and thereby Vitamin D production. Just a thought. Best wishes,

    • greensleeves

      Sorry, but if anything, the current science comes out the other way. Go to Google Scholar and see – most of the studies – albeit perhaps poorly done – argue that that low-carb “causes”/”is linked to” depression. To try low-carb for depression is definitely an N=1 experiement. But what can happen? If you start to feel worse, just eat a potato and stop low-carb. Seems like an easy experiment.

      • I think you said it yourself…”albeit perhaps done poorly”…emphasis on POORLY.

    • Sam

      All this talk of do what feel good remind me of a slogan of a health insurance company “WHAT MAKES YOU HAPPY MAKES YOU HEALHTY”. It always comes to mind how many alcoholics and smokers feel that way. When doing N=1 experiments one needs to use the correct parameters for evaluation or the long term results could be disastrous.

      More about N=1 self experimentation


    • DHackam

      Unfortunately, carbohydrates are potent stimulator of serotonin and dopamine release in the brain, the latter acting in the “pleasure centres” of the brain (e.g. amygdala). Acute carbohydrate withdrawal can precipitate exacerbations of bipolar disorder or depression (I have read several case reports on this). Some would suggest tapering carbohydrates very carefully on this background.

      • No doubt, but I think the interesting question is not so much the acute withdrawal (acute withdrawal of almost anything hurts), but the “new” baseline without them?

    • Kayla

      Just wanted to say that low carb and not enough fat definitely caused depression for me. But high fat (70-80%) and low carb is like a magic happy pill for me (n=1) – anxiety and depression gone! I was never clinically diagnosed with either, but sure noticed when all of a sudden I was feeling terrific, more energy, more resilience mentally and emotionally, and no anxiety (which had plagued me since childhood). I would say give it a try, just make sure to keep the lovely saturated fat intake really high. I would agree that tapering gradually would make sense. I gave up wheat a year before I officially went low carb – induction (20g of carbs/day) was a breeze, probably only because I was already lowish carb beforehand.

  • Edmund Brown

    Thanks for another informative article. I hope your labors here in the cyber-world feel as rewarding, or perhaps more rewarding, than your practice as a surgeon. If you brought the same level of dedication to your practice back then that you do to this nutrition thing I’m sure you did right by your patients. I for one am benefiting from your blogging, so thanks, I look forward to each week’s installment.

    I also thoroughly enjoyed “Bigger, Stronger, Faster”, and recommend it now and again.

    • Nice to hear. Thank you. Surgery, of course, was very rewarding in many ways as results were so immediate. Hopefully, this blog can ultimately help more people, though. Hard to “scale” surgery.

    • Just to throw my support as well, I hope you never tire of these blogs, Pete. I could devour one a day if it were possible. You have definitely helped me, which has helped those around me. Multiplication going on here — I hope NUSI is successful in reaching the medical dr’s who need to hear it most.

      • Thanks so much. If I could, I’d actually be happy writing one a day, but I’m actually struggling (from the standpoint of time) to write one a week. Another reason I’m so grateful for the comments to keep the discussion going between posts.

  • Scott

    So supposing someone were to want to use the “cleanest” of those performance enhancing carbohydrates, do you have any insight into what to use/avoid? My general understanding is one in favor of potatoes/yams, but I’d be interested to hear your opinion.

    On a similar note, approximately how much carbohydrate consumption would you say is necessary to keep muscle glycogen stocked, without any unnecessary extra?

    • Lengthy topic. Like I suggested in the post, though, if you were really trying to compete at the top levels of sport, I’d suggest killing the sugar and processed foods. No wheat. Get about 30-40% of your calories from carbs, but excluding these groups I mentioned. Huge improvement in health for virtually everyone, coupled with a performance improvement. You’ll “miss out” on some things (e.g., perks of ketosis), but I think the trade-off would be well worth it for the pure performance gain.

  • Ughh just had a long post that didn’t go through, so going to try this again.

    Two questions for you:

    1.) Since we’re talking about athletic performance, and most average folks use athletics to either burn fat, keep them in shape, or get healthier, what exercises would you say are optimal for fat burning in ketosis? If you’re not in ketosis, it seems like anaerobic exercises like weight lifting or short bursts of energy like tire lifting or sprinting burn fat at a much greater % compared to aerobic exercises like spending an hour on the elliptical which would burn a much higher % of glycogen. Are the rules the same, or does it matter what exercise you do if you’ve already switched your body to fat burning mode for almost all energy?

    2.) Concerning the zone of misery, can you reach the zone by just eating too much protein even if you keep your carbs to almost zero? In other words, do you have to BOTH eat too much protein, and just a little too many carbs (but not enough to fuel your brain), or can you do it with too much protein alone?

    Glad you referenced BSF, a great, practical look at AS.

    • 1) Very hard to find great evidence that exercise as the sole vehicle for “fat burning” works well. Most folks (myself included, prior to carb reduction) get so damn hungry within about 24 hours of the killer workout, that they more than make up for it. So I’m always hesitant to think of exercise in terms of calories burned. I think of the opposite — calories supplied for energy. This is the big advantage. Look at the RQ data from Part 4 of my personal journey. Look at how much more fat I can ACCESS at even the highest levels of exertion. It’s not so much that I’m exercising to burn more fat, I’m burning more fat to ALLOW me to exercise for much longer. See the difference?

      2. ABSOLUTELY! This was my life for 8 weeks. Very little carbs (maybe 20-30 gm/day), but 250-300 gm/day of protein. Ugggg.

    • Claudia

      Don’t know if it’s due to individual differences or not, but after I read about reducing protein here on the blog and did so, I had little or no zone of misery on my way to ketosis (7 wks of <20g carbs + fat).

      • Individual differences, in my experience, are enormous on this particular point.

  • Dave

    Yeah I think you nailed it when you talked about your own reasons for choosing a ketogenic diet. I get tired of people suggesting that I am hindering myself by training for a marathon on a low-carb diet, when I’ve been running races for 4 years (2 fulls, 4 halves), and only low-carbing for 4 months, so I’ve certainly given carbs a chance.

    I have much more endurance today than I did 6 months ago. A few weeks ago I set a PR on my 10K time during a training run that was meant to be just a tempo run. And my prior PR was a hard fought race where I was tapered and carbed up from about a year ago.

    Then I get the response, “well yeah you probably improved, but it could be cause you lost some weight but you’d still do better on high carb”. And I say, “possibly, but if I can’t stop gaining weight on high carb it won’t do me any good”.

    • On the list of “Greatest failures of human understanding” the inability to understand nuance has got to be near the top of the list. An idea that is incorrect but simple to understand will almost always trump a correct, but more nuanced, explanation.

    • Birgit

      Dave, so glad you posted this. Just the encouragement I need to start training for my first marathon (hopefully late this year) and having recently switched to a ketogenic diet. 🙂

    • Dave


      Good luck on your journey. But just be aware my low-carb diet isn’t ketogenic like Peter’s, as I do weekly carb feeds to fuel my long runs. Part of it is because I don’t want to be too restrictive in my diet (because of all the temptation out there), and part of it is because I want to perform optimally on race day and be prepared to burn glucose when I need to. Most of what I follow is derived from the concept of ‘train low, compete high’. But I’ve been told my approach is stupid by some and won’t work.

    • Birgit

      thanks for clarifying. I train at a low heart-rate (180-age) only but will keep in mind what you said when it gets closer to racing day. 🙂

  • Sam

    Peter I don’t know why people need to attack low carb when it has proven that it provide so many health benefits for so many people, as well doing better on any fair trial when compared with other diets. The analogy it always comes to mind to me is that of pharmaceutical drugs. That even potent ones have a very wide rate of response and different effects because of genetics and metabolic condition of the person treated, why diet will be any different. I firmly believe health wise low carb is the best, it has been for me and everyone I have recommended they try it. But is just common sense that it will not be as easy or get the same exact results in everyone.

  • Mark

    Another good post from really good blog. I’m glad I found you.

    Two years ago I dropped close to 70 pounds on a low-carb diet, and decided to run a marathon. I’m a pathetically slow runner, and only had an interest in finishing the marathon, not in my time (which was slightly over five hours). As I got into longer runs during my training, I tossed aside my carb restriction and took the advice that I needed carbs to make it through my long training runs and the marathon itself. I assumed it helped my performance, but I have no point of reference as to how well I would have done if I had trained and run on a carb-restricted diet.

    Now I plan to running another marathon in the Fall, and I’m currently back on a reduced carb, no sugar diet in order to lose the twenty-five pounds I’ve put on since I stopped my carb restricted eating. Much of what I’m doing is based on the information I’ve gleaned from this blog. My wish is that I can make it through the training and the marathon without increasing my carb intake, as I love how I feel and look when I’m not eating the junk. I couldn’t care less how fast I go, although an improvement would be nice. So far, I’m up to about 40 miles per week in training, as well some strength training, and I’ve felt great. Can I assume that my body’s ability to adapt and utilize fat will continue to improve, and I can continue with my same diet (less 50 grams a day)?

    • Yes, the more you reduce carbs, especially once you cross that binary threshold into ketosis, your ability to access your own fat stores goes up dramatically.

  • Tom

    I have had a few articles pass my desk from a few sites on intermittent fasting and lowering body fat. admittedly I have some work to do on sleep and lowering protein intake. I’m currently about 66% fat, 8% carbs, and 25% protein and never feel the blahs. I have found lately that I don’t need to eat as much as I have been (especially if my fat intake is up for the day) so even though I don’t gain any weight I eat because I can. I’m slowly going longer between meals and only eating when I am hungry.

    I run 3x a week and swim 3x a week. hitting the pool or pavement by 0600 so I am semi fasting when I do work out and have a large breakfast afterwards.

    I’m wondering about IF – why and if it is effective and if the old saying of don’t eat after a certain time has some truth to it.

    Any thoughts? Suggested experiments.

    BTW, I am getting a DEXA scan as well as full blood, stress, etc done the first week of May as a baseline.

    • Tom, I’m actually doing a series of IF experiments on myself. Because I’m ketotic, it’s shockingly easy for me to avoid food for 12-24 hours, not only without any hunger, but also without any loss of mental focus or energy. I check my blood levels of glucose and B-OHB every 2 to 3 hours during a fast and then watch what happens when I re-feed. I’ll probably write about this in the future.

    • greensleeves

      “Because I’m ketotic, it’s shockingly easy for me to avoid food for 12-24 hours, not only without any hunger, but also without any loss of mental focus or energy.”

      I think this is a guy thing. Being female, if i don’t eat, I get grumpy. All my girlfriends are the same way. Now that I eat 35 net carbs a day, I don’t turn into the screaming maniac I used to every 2 hours if I couldn’t grab a third bagel, but it’s still not a party. All the low-carbers extolling IF seem to be guys. I have yet to find a woman who sees much benefit from it.

    • Peter you must spend an absolute fortune on those Precision Xtra ketone strips. Is there some secret to getting a cheap supply?

      • Not really. Yes, I’m LONG on ketone strips…

    • KellyB

      I have to respond to greensleeves. I’m a woman and have been IFing on and off (obviously) for the past year and a half, and it doesn’t make me cranky at all. I tend to do 20-ish hour fasts and I have some mild hunger at about the 17-hour point, but it goes away in about 10 minutes and when I do finally eat, I’m not ravenous. Mental focus is good throughout, as is energy.

    • Sue

      Just for the record, I am a woman who has no trouble at all fasting for up to 24 hours. I’ve been eating LCHF for nearly 10 years, and have done periods of regular fasting in the past. Now it’s circumstantial, I know if there isn’t an opportunity to eat, or access to good food, it really won’t hurt to just not eat.

  • Gary

    Did you see that Dr. Lustig was also on Good Morning America? The sad part is my parents watched it and they only took one thing away. Eat a shit load more fiber.


    • Ugggg. I’ve also been told, based on 60 Minutes this week, that the “main takeaway” is that HFCS is no worse than sugar…load up on the HFCS, right?

    • In fairness to Lustig, what he said on 60 Minutes is that table sugar and HFCS are equally bad, and both are poison (he said “poison” or “toxic” one or the other, or both.) He was specifically making the point that cane sugar is not a healthy alternative to HFCS, as some people seem to think.

    • Alexandra M

      Amazing. When the point is that sugar is no better than HFCS. It reminds me of those people who interpret “works no better than placebo” as “works as well as placebo” to show that their favorite snake oil is effective.

      As you said earlier, Peter, this is a real shock to the system for some people and denial will take some bizarre forms.

  • I was a staunch ‘anti-carb’ believer for the past year and a half, having dropped 65 pounds in 8 months and easily maintaining it without having to workout at all. Problem is – I feel better and thus *want* to workout, and especially lift weights. I was able to do light cardio (walking) on less than 50g of carbs per day (usually less than that), but once I started a weight training program (under the tutelage of a personal trainer, with only compound lifts and definitely not over-doing it), it was like I ‘hit a wall’ – no energy, very lethargic. So the first time this happened I gave up after a couple of weeks of doing a full-body weightlifting routine just twice a week. Waited a month, figuring I over-trained. But, sure enough, the next couple of times I tried lifting the same thing happened.

    A week or so ago I decided to try again with the weightlifting routine, except this time I took a risk and forced myself to eat a humongous sweet potato right after my lifting routine, and I’m also eating a banana a day, and a full-fat greek yogurt (still has carbs though) every day. This is in addition to the carbs I always got from veggies.

    Results? It’s only been two weightlifting sessions this week so far, in-between cardio/sprinting sessions, but I *feel great*. I was worried about the added carbs causing weight gain, and the first few days they did (I assume water weight), but if they allow me to continue to workout hard then it will be well worth it.

    I am squarely, at least for now, in the ‘safe starches’ camp. At least if ingested within an hour of a weightlifting routine.


    • Mark, I think it’s awesome that you’re doing these experiments on yourself. As you know, I’m a huge proponent of them. Please keep us posted and update us on all aspects (e.g., performance, body composition, lipid profile, inflammation).

    • Re: the Greek Yogurt — Volek and Phinney point out that true cultured yogurt only has half the sugar it’s labeled with, because producers are required to count all the lactose that goes into it, but half is fermented away. (Jonny Bowden makes a similar claim). So I’m counting my Fage Total as only having 4 carbs instead of 8 … hope that’s accurate. (Not that I should lose sleep over 4 carbs.)

      • That’s how I do it. Have of the lactose is converted to lactate.

    • Alexandra M

      I’ve been letting my yogurt ferment for a full 18 – 24 hours to convert as much lactose as possible. Do you think that’s overkill? It usually sets up in 4-6 hours.

    • Alexandra M

      Also, from 1/2 gal of whole milk yogurt, I strain out a quart or more of whey, so I have no idea what’s leftover. I’ve seen this question posed on many boards lately and nobody seems to have a definitive answer.

    • Mark,

      as a Former Fat Boy myself, I have found the carbs absolutely must be pre-, not post-, workout. Getting the carbs pre-w/o fuels the work you’re about to do, and the w/o burns off those carbs. Why get carbs post-w/o? Replenishing that glycogen will only inhibit fat-burning, and is not necessary for muscle recovery (except for “hard-gainers” maybe).

      I explain it more here


  • Pingback: Success in Using Performance-Enhancing Drugs | Low Carb Learning()

  • Would you mind explaining what you mean by “binary threshold”? Thanks.

  • Would you mind explaining what you mean by “binary threshold”?

    • Sure. “Low carb” is a relative proposition. If you eat 600 gm/day (like I used to), then reduce it to 400, then to 200, you can probably expect to see relative improvement at each step. Ketosis is “all or none.” Either your body is making sufficient ketones to satisfy your brain, or you are not. In general this occurs when blood levels of B-OHB exceed 0.5 mM, which is only obtained with consistent consumption of <40-50 gm/d of carb and <125-150 gm/d of protein.

    • Michele

      Peter, this comment is concerning your response to post #31 “Sure. “Low carb” is a relative proposition.” How does this quick summary for the elevator speech I once mentioned sound?

      “…getting past the binary threshold, a.k.a. being in ketosis, is a function of where you are in terms of goals and genetics”

      For example, due to your wife’s high goals and good genetics, it is not a necessity for her to be ketotic. Rather, simple carbohydrate restriction suffices for someone like her in the upper-right-hand corner.

      • Correct. My wife has eliminated most sucrose and HFCS, and also eats almost no processed foods, but she still gets 40-50% of calories from carbs. Same is true of my daughter.

  • Thanks. That’s what I thought you meant, but my tendency is to overthink and make things more complicated than they really are…thus the desire for clarification. 😉 So, if I’m eating less than 30g/day of carb and well under 100g/day of protein, is it pretty safe to say I’m in ketosis? I haven’t seen any weight loss for almost a week, so I’m going to drop carbs down to 15g or less and protein down to 60g or less while increasing fat still more and see what happens. I am a cancer survivor and my body just doesn’t respond post-chemo the way it did before. Very frustrating.

    • I can only imagine. It can really take a while to get your body to “re-learn” how to prioritize fat burning rather than glycogen burning. It took me about 8 weeks to “adapt” to the process, but the time is highly variable.

  • Great post once again Dr. Attia. Your second to last paragraph summed it up well. It’s something any fitness and nutrition professional should keep in mind when they work with clients. The average person wants to perform better, lose weight and be healthy. At a certain point, you have to choose peak performance or optimal health and the training and nutrition should support that choice. Unfortunately, too much of the nutrition and exercise education fitness professional get comes from the standpoint of performance enhancement versus health and vitality (which would also help with weight management).

  • Marilyn

    I just looked at the Dashti report and one thing occurs to me: In the introductory material, it is mentioned that the fat content of the diet was “20% saturated fat, and 80% polyunsaturated and monounsaturated fat.” I’m guessing that many people reading that would immediately think “20% butter, and the rest canola oil and olive oil.”

    I think there’s a common misconception that all animal fats are saturated. I have an old book here, Pinckney/Pinckney, “The Cholesterol Controversy” (1973), in which they state, “. . a great many foods fried in lard (AN ALMOST TOTALLY SATURATED FAT EXTREMELY HIGH IN CHOLESTEROL). . .” [my emphasis]. Yet Mary Enig analyzes pork fat as about 40% saturated, 50% monounsaturated and 10% polyunsaturated.

    Looking ahead: I know that when you report on your findings, it will be necessary to report some things like “20% saturated fat, and 80% polyunsaturated and monounsaturated fat.” But if the sources for some of those polyunsaturated and monounsaturated fats are animal foods, I hope that fact can be communicated. I think there are (at least) two myths you will need to dispel — that carbs are very good for us, and that animal protein and fats are not very good for us.

    • Yes, this is part of a much broader problem. As you point out, a significant amount to animal fat — even from the “deadly” food, bacon — is NOT saturated. What most don’t realize is the “bad” fat from animals is not the saturated component, but rather the omega-6 polyunsaturated that is more abundant in grain-fed (vs. grass-fed) meat.

  • DHackam

    Indeed. Gary points out in his last book that 75% of the fat in lard is identical to the fat contained in olive oil, and only 25% is saturated fat. Hence, praise the lard (as the bard says).

    I am very eager to see what my chemistry will show. After a 15 hour fast today, I did LDL-P, VLDL, non-HDL cholesterol, apoA1, ApoB, lp phenotyping, insulin, homocysteine, hsCRP. This comes on the heels of about 4 months of very low carb dieting (<20 g per day). I have lost 33 lbs and also eliminated caffeine and artificial sweeteners. The proof will be in the pudding – if my lipids (LDL-P) has shot up from all this dietary cholesterol and saturated fat, I would rather take a statin than modify my diet (I also began with high triglycerides, low HDL and high hsCRP – with borderline white coat BP – suggesting metabolic syndrome).

    I am enjoying reading this forum immensely.

  • Michael V

    54 year old male never was, who loves to train and compete in masters track and field, specifically the hammer throw. Duration of a throw is under 4 seconds. Am I deluding myself to think that since I am working the anaerobic alactic (ATP) energy pathway, glycogen and by extension carbohydrates are not as big of an issue for my athletic performance.

    • Might help to distinguish between training (largely anaerobic + creatine-phosphate, but some aerobic, especially if you’re metabolically efficient) versus actual competition (all creatine-phosphate for 4 seconds). Glycogen plays a bit role in anaerobic, but not C-P.

  • Martin

    And how about supplements such as BCAA, Glutamine, Creatine, L-Carnitine, Beta-Alanine, etc. They are chemical compounds. If taken as supplements, i.e. not synthesized by the body or naturally present in the real food we eat, can be regarded as drugs. They do enhance performance.

    Do they fall in the same category, just at a different, more benign side of the spectrum?

  • Debbie


    Please, someone write to Frank Bruni. He’s a New York Times columnist, and ex-Times restaurant critic. A great writer, but giving up red meat due to gout.

  • Debbie

    I really wish the NYT writers would stop dispensing questionable diet advice. Mr. Bruni’s gout is probably caused by many things, obesity being the No. 1 likely factor. Red meat is a red herring, probably not nearly as much of a factor as obesity, excessive consumption of alcohol and excessive consumption of sugar, juice and refined carbohydrates. Cutting red meat consumption to eat more spaghetti may be politically correct but it is is likely to lead to even more obesity and serious health issues. Mr. Bruni needs to get his weight down, and whatever diet helps him to do that is what he should eat for now. If he’s like most Americans, he has a much better chance of losing weight on a carb restricted diet than by eating more pasta as he suggests here. One wonders if the spirit of Jane Brody, who for 25 years advocated a terrible high-carb diet, still influences the NYT newsroom.

    Most of the comments are telling him eating meat is bad and they stopped and feel great and lost weight – but here’s one we like.

  • Dave Nelsen

    I have a friend I used to work with who has gone in to competitive weight lifting. Apparently everyone in this sport takes steroids. I think he’s gone off the rails trying to beat his personal bests and will end up significantly shortening his life. I don’t understand his obsession – there’s no money in it and he is only improving his personal bests.

    On an different note, I met with my primary care Dr. yesterday. I was asking for the NMR lipid profile test. She had never heard of it or of the concept of LDL-P and the other breakdown data you get from this test. She was a little skeptical at 1st and she needed more info as she had never ordered this test. In the end, she thanked me for bringing this information to her. She 1st looked for the test in a medical reference book and couldn’t find it. I pointed her to an internet site and she seemed intrigued. It’s going to take education and patience to get this message out. She did want to know if I was following the advice of someone on the fringes. I referred her to this website and Gary Taubes site.

    • Dave Nelsen

      One other thing. For some reason this weeks post by Peter shows only 1 word per line when I view it on my laptop. Views ok on my desktop at home, but not on my laptop and everything worked ok on the laptop before this weeks post. Don’t know if anyone else has seen this. The comments show normally, only the post has 1 word per line.

    • Glad she has an open mind. Point her to this: http://www.lecturepad.org/

  • Thank you very much for the link to LecturePad. Great 4 part presentation there by Dr. Tara Dall on advanced lipid testing. I was also introduced to ClevelandHeartLab and their capabilities. Their advanced lipid testing of LDL-P by NMR also does insulin resistance.

    • John, your mission, should you choose to accept it, is to get as many doctors as possible to watch the lectures in this series by Drs. Tom Dayspring and Tara Dall (I call them TD-squared). Everything I know about lipidology I know from them.

  • Eddie Friedman

    Peter, I am being presumptuous, intended in a friendly way 🙂 figuring this is popular in this “community.” All the best, Eddie


    • Hi Eddie Thanks for the link. I was not aware of this new book by Jeff Volek. I have ordered it from Amazon.

  • Dr. Attia,

    I disagree about treating carbs the same as PEDs, for two reasons:

    1) “what this blog is about” is the damage of consistently high carb intake, all day every day; timing your carbs to sync up with exercise may be completely different. (there may also be damage specific to insufficient fat intake.. but I digress.)

    2) Our ancestors ate fruit in the tropical zone for millions of years, didn’t spread to the temperate zone til 40kya, and started eating carbs on a regular basis again 5-10kya.

    I took 4 inches off my waist after reading GCBC, and I’m grateful to GT for his work. However, although most people do best on a diet with less than half of total cals from carbs, I think ketogenic is inappropriate for the vast majority.

    If people are going to get more than 50 g carb most days, it becomes even more important to sync that carb timing with exercise.

    • Jeffrey, I think you missed the point of this post, which reflects much more poorly on me than you, since I wrote it. I apologize. At no point in this post or others do I suggest everyone should be on a ketotic diet. Yes, I am ketotic, and after a 2 year self-experiment of gradual carb reduction I’ve found the benefits (e.g., mental acuity, sustained energy levels, reduction in disease risk) outweigh the costs (e.g., loss of some physical performance, “difficulty” of getting 80-90% of my calories from fat). If you’ve been following my blog, and you’ve read the work on Volek, Phinney, Steffanson, Schwatka, Eades, Sisson, and others, you’ll note that at least some individuals CAN in fact do the most strenuous exercise without any carbohydrate ingestion (i.e., <30-50 gm/day). In particular, the work of Steffanson and Frederick Schwatka is particularly remarkable for the study of the Inuit population -- a population that ate zero carbohydrate and carried out a life far more physically demanding than anything we do. However, this issue was not the point of my post.

      Here is my point: Carbohydrates improve physical performance. So do anabolic steroids and EPO. Carbohydrates have side effects. So do anabolic steroids and EPO. Does it mean we shouldn't use EPO or anabolic steroids or carbohydrates (ignoring the highly arbitrary and illogical legality of anabolic steroids and EPO)? No it does not. It means we need to balance the costs and the benefits of what we do. If being a little faster on the weekend ride or the pick-up game matters -- and if it does, that's fine -- they maybe one should be ingesting more carbs. It's just completely illogical to think that doing so is completely benign or that doing so is somehow "smarter" than using anabolic steroids.

      I'm not talking about "abuse" of anabolic steroids or EPO. No doubt you can more quickly and profoundly demonstrate the toxicity of these agents than that of carbohydrates, but most people who use anabolic steroids and EPO do just fine.

      I completely understand your point about timing and ways to mitigate the deleterious effects of carbs. But that is no different than what an athlete does when they cycle on and off different anabolic agents -- they are optimizing performance while trying to minimize risk.

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  • Hey Peter,

    Seriously impressed with this site and your work.

    I’ve my own ideas on diet as it relates to health and performance, but we’d share many common themes.

    My concern isn’t really longevity but performance at soccer. So I need bursts of speed and endurance.

    I also like having a relatively normal diet so I don’t feel like I have to be obsessing over food and too picky. Some people don’t have this issue, but I do.

    Also, a lot of the positive results you’ve experienced are also gained by people that simply lose weight, by any method.

    I’ve used intermittent fasting myself (24 hrs once or twice per week) and the health markers are proven to drastically improve with a big reduction in body fat. So that has big longevity benefits in itself.

    However, I’ve no doubt that a high fat, balanced protein and lower carb intake is better for health and performance.

    Are you aware that fats drastically improve the endocrine system? Male testosterone is hugely improved by high fats by SHBG (Sex Hormone Binding Globulin). Your results could be as much to do with these factors as removing carbs.

    I try to start the day with two tablespoons of coconut milk, fruit and a protein. That way when I control calories with intermittent fasting I’ve cut carbs and not fat and protein, thus changing my diet to maybe 40% carbs and low calorie.

    Fasting also greatly improves the process you talk about, hormone balancing, insulin reduction, insulin sensitivity etc.

    All improved by losing body fat but fasting amplifies the effects as well.

    So I’ve a different take, but many similar themes. I find it easier to live my way and I like that I have a base of carbs for anaerobic bursts of power.

    However, an awesome site, continue your great info and studies. The exact figures and studies you’ve done are especially informative and impressive. Well done.

    • I just want to edit the above post a bit. I was a little off hand in describing how I eat at breakfast.

      My first eating of the day has more fat than just two tablespoons of coconut milk.

      I also have a tablespoon of cod liver oil, two tablespoons of chia seeds, a superfood supplement of fruit and veg called ‘source of life gold’ which is low calorie and unbelievably comprehensive and nutrient rich.

      I often eat eggs as well.

      And then I have about 50 grams of protein in a shake called nitrofusion (plant based)or some type of chicken because I like to have an intake of 70-140g of protein per day due to my training regime.

      For the rest of the day I eat low calorie and medium level of carbs with one or two 24hr fasts per week.

      I’m convinced high fat, calorie control and calorie cycling (fasting and ‘big’ feeds) has major positive effects due to our genetic profile/evolution.

  • I know you say people can have a different genetic response to diet but if you were to become a sprinter, what diet would you have?

    Would it be 40% carbohydrate all the time or would you only use generation ucan prior to an event and after?

    Or carb load on generation ucan generally on and reduct fat intake accordingly?

    After reading your posts I am interested to hear your thoughts on this.

    • If I were trying to optimize for sprinting, it would probably be closer to the 40% or so, plus other supplements like creatine.

    • Thanks man.

      And sorry if you felt I was launching on you a bit.

      I couldn’t edit the thing to sound a bit better as it didn’t give me enough time.

      I’m really impressed with this site.

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  • Peter, this isn’t exactly on-topic. It’s about optimizing your sprinting capacity. In your last comment, you said you’d go with 40% carbs. If you’ll indulge me, I’ll show you why that’s the wrong way of looking at the problem.

    Sprinting is not about fuel efficiency, but about power output. Take a car for example. Everybody knows a small engine is more fuel efficient than a large engine. It makes sense. A small engine is lighter, therefore it needs less fuel to get the car moving. But the assumption is that a small engine will go in a small car. If we put a large engine in the same car, but keep the total weight the same, both the large and small engines will be just as efficient. That’s because fuel efficiency is not determined by the size of the engine, but by the ratio of total resistance and power. For equal resistance, we need the same power, therefore the same amount of fuel. Granted, a large engine has bigger moving parts therefore more internal resistance but the difference is marginal compared to the differences between a small car and a large car.

    Sprinting is about acceleration. So while a smaller engine might be more efficient for steady-state, it just doesn’t cut it for finish-line acceleration. Yet a bigger engine isn’t that much less efficient for steady-state. In fact, it could be more efficient by virtue of having more power, therefore needing less effort for the same steady speed.

    Talking about carbs for sprinting is like talking about nitro for car engines. It works but it comes with its own set of problems.

    The real problem? Muscle size. Solution? Bigger muscles. Since we’re talking about only a small portion of total body weight – the legs – the potential increase in power output probably more than makes up for the potential increase in weight. It’s like putting in a V6 that puts out 300hp, but weighs only 100 lbs more than the inline 4 that puts out 200hp, in a car that weighs 2,000 lbs. For a human male, that would be like adding 5 lbs of leg muscle, in a body that weighs 180 lbs. And then consider the fact that dietary fat weighs half and doesn’t detrimentally affect hormones as carbs do, running out of fuel mid-race is not a problem even though bigger muscles need more fuel.

    My own experience seems to confirm the idea of bigger muscles to improve endurance. I play golf. It takes endurance to walk the course. But it also takes strength for every stroke. Halfway in the round, I’d get tired and didn’t have enough strength to perform the motions with as much precision so my score suffered. I decided I’d get stronger first. It gave me more endurance for some reason. Since I was stronger, I didn’t need to exert myself as much. I’d stay fresh the whole round, and I had enough strength to the end, my score improved. I also ate a quarter pound of butter for lunch.

    Basically, endurance capacity as a function of strength/effort. And sprinting capacity as a function of pure strength.

    • Addendum. About 5 minutes ago, I read a post on lowcarb.ca forum from PJ. She said something about exercise-induced asthma. It got me thinking. First, check this out:


      The idea with this drug is to reduce the number of fat cells to grow leaner. Fat cells, like any other cell, need oxygen. More fat cells, more oxygen. But fat cells don’t give us strength, endurance, and basically don’t do much besides supplying us with a steady stream of fuel. If we have more fat cells, they consume more oxygen for no good reason. This oxygen could be used instead by all other cells to give us strength and endurance. More fat cells also means more fuel supply to all other cells but also more oxygen needed for oxidation by all those other cells. Basically, being fatter means oxygen deprivation for all other cells.

      Oxygen isn’t only needed for strength and endurance, but also for health. Everything that keeps us alive needs oxygen to work. If we’re fatter, there’s less oxygen for that. In the monkey study, they showed health improvement when their fat cell count was brought down. It makes perfect sense.

      Anyway, for sprinting optimization, reduce your fat cell count. Less oxygen to fat cells, more oxygen to muscle cells, more strength, more endurance. Brilliant.

    • Good points, but I guess it depends on how we define “sprinting.” Because I’m kind of an ultra-distance wonk, “sprinting” for me is probably middle-distance for most. In swimming, a sprint would technically be the 50, though I’m really talking about optimizing around the 100-200, which is far less CP and almost pure anaerobic.

  • lockdownd

    Hi Peter,

    Loved the post. Learning about this stuff from your blog and references is like drinking from a fire hose. Had a question regarding your on bike nutrition during a long bike ride. My first long, hard group ride after my high fat, moderate protein, low carb breakfast didn’t go too well. The next time I ate a big bowl of sugar cereal and drank sugar-water the whole ride … much better. But I don’t want to derail my keto-adaptation from the week and keep yo-yo’ing. What do you eat (if anything) on your long, hard bike rides?


    PS. I’ve had some random thoughts on your blog which I’d like to share. It’s kind of a grab-bag.

    1. Please monetize your efforts to at least cover your costs. There are a number of people making a living doing what you’re doing. Would hate to lose you due to the financial burden it places on you and your family.
    2. Is there any data out there that shows increasing blood sugar or insulin for a large number of people over the decades? The United States Military has tremendous data from all recruits which spans decades. Their data shows alaming trends in size and physical fitness of recruits. I assume they have no blood data but I’m curious.
    3. My niece just graduated from med school. We talk nutrition at Starbucks while she drinks a carmel-machhiato and I have full cream latte and we both look at each other like we’re crazy. You mentioned somewhere that if 20% of physicians would buy into low-carb as an effective and safe modality to try with their patients that that may be a tipping point. Why not get to the source and try to get med-schools to teach low-carb instead? I’m sure you’ve thought of that but wanted to throw it out there.

    • Eric, Ketoadaptaion takes months, if not weeks. Certainly not days. Once you’re “there” you don’t need much on a long ride. I eat some salted nuts for sodium and fat and individual packs of cream cheese.
      I appreciate your thoughts on monetizing the blog, but for now I’d like to keep this as free and clutter free as possible. I will ask something in return, but that’s for another time. Not much observational data on insulin levels, since they are not routinely measured. As for #3, this is a small part of a much larger goal of NuSI. Many steps needed, first.

  • BA

    With regard to performance enhancement in general, do you have any opinions on creatine supplementation while on a ketotic or general carbohydrate-restricted diet? It seems to be a generally-accepted notion that you need an insulin spike accompanying the creatine load for maximum benefit, but I am skeptical.

  • Peter, I am new to you and your blog, but not to Taubes, Lustig, et al and their great work regarding sugars, carbs, etc. This post seems the best place to ask my question. I’m a personal trainer, group fitness leader, and (recovering) public health professional. I’ve been taking people outdoors for their exercise since 2003 and am curious to know what you think of a performance enhancer about which I haven’t found any discussion on your site: nature and sunlight. Are you familiar with the research on the added effects on our mental and physical performance and health when athletes and nonathletes are active outdoors? Do you lend much credence to it? I’m not aware of any research related to weight/fat loss, but it seems here too there might be an additional effect, via the stress/cortisol/insulin connection. The thinking is that we evolved to be outdoors in sunlight, much more than we currently are, and this is having health consequences (see especially the books by Richard Louv on nature deficit disorder and by Eva Selub on nature and the brain). Deserves its own post, I think.

    • Nancy, I’m especially knowledgeable in this subject, but it’s hard to make an evolutionary case that such factors don’t matter. Check what Mark Sisson or Robb Wolf have to say.

  • Scott

    Ketone Help. I started LCHF 7 weeks ago. Immediately dropped 10 pounds and need to plateau as it continues to decrease, now a t 161 from 175.. I’m super active cycling and working out 5 to 6 days a week.I got the meter and tested Glucose (out of curiosity) 20 min after a meal sugars at 70, the next day (yesterday) tested Ketones mid day 0.3. Today I blood tested first thing in a.m. and Ketones are 0.6, which sounds very low. I appear to exhibit all the signs of being in Ketogenic state, no food cravings, frequent urination (which is decreasing, thankfully) was keeping carbs less that 50 per day, now somewhere between 50 and 100. Extra are pre, post and during more intense cardio. work (2 to 4 hours). I’ve definitely lost strength in regard to cycling, hoping it will return??
    What does low Ketone blood measure mean in regard to Ketogenic state?
    What other fats can I eat to avoid continued weight loss (I may be eating too much protein now?)
    And the big question, how does the body utilize fuels in an Anaerobic state if there aren’t adequate sugars availabe for fuel???

    Thanks for any input…

    • Definitely a lot of folks here, Scott, who can help you out.

  • I’ve just discovered your blog and I find it amazing! I’d say that I’m more or less like you, with the difference that I do not have any medical background, just the data I read everywhere, but we seem share the very same concerns about finding the perfect way to eat healthy. I’m a 29 year-old software engineer. Until my first 20ies I’ve never done any sport and were eating only crap, of course full of sweet and carbs. Then I started bodybuidling and that alone made me improve a lot and become stronger and leaner. Then I started to care about nutrition and also began eating “well” and I put it this way because I’ve been following the common practises of “low-saturated-fat/high carb/high protein” typical in body-builder diets. 3 years ago I started to enjoy participating endurance races and now I can say I’m a lot more into endurance running than weight training but I maintain the two. I’m 172cm tall and 62 kg with 11% bodyfat or so I think.

    It has been several years now that sometimes (pretty randomly indeed) I felt very tired, bad mood, irritable, and very spaced out, light-headed. I went to the doctor but the blood tests showed pretty normal. Also recently starting last year I started to feel like numbness in both hands and feet. I did my research and being worried by a possible kind of neuropathology due to excess carbs I started trying to reduce them and even if I find hard to get under 100gr a day of carbs (I’m a vegetarian for personal believes so no meat/fish/whatsoever is alive, dairy, eggs and derivates are ok) I can tell I’m feeling better recently.

    The only problem now I see is that my athletic performance has been decreasing a lot this year. Last December I ran a PB on the 10K with 35:25 and managed in some other races to get 36 or low 37. But recently I’ve felt a very hard impact on performance, now I struggle a lot just to run in 38′ and I have the feeling that the carb reduction (even if not near the 50gr day to enter full ketosis) may be the cause. I’ve also been diagnosed with a little bit of aenemia so difficult to say if one, both or any may be a cause.

    Well, that’s my story. I’ll keep an eye on your blog and maybe keep you informed about my observations on the subject over time if you may care.
    PD: Sorry for my poor english.

  • William

    Thank you for your invaluable commentary, and open minded approach to the topics you discuss.
    I have a couple of questions:

    1) You mentioned in a response to one post that ketogenic adaptation can take months. After starting a ketogenic diet in May 2012, I noticed that when doing my 4 mile run that I would have much greater energy after a “cheat” day in which I consumed large amounts of carbs. Now, after being on ketogenic diet for 7 months, I don’t get that same performance enhancement effect after a “cheat” day. Would this be explained by having more fully completed ketogenic adaptation? As a follow-up, I also notice that I feel sort of depressed after a “cheat” day. Do you think this is somehow related to serotonin levels/regulation?
    2) I have noticed that I can remain in ketosis (tested using ketostix) and eat a relatively large amount of natural peanut butter, and raw nuts such as cashews, pecans, and almonds – sufficient quantities for total carb intake to approach 100g/day. Is there something in peanut butter/nuts that effects carbohydrate metabolism, or is it more likely that my body chemistry simply allows me to eat these quantities of carbs and remain in ketosis?
    3) You discuss B-OHB levels in some of your posts. Is there a simple testing method for B-OHB? Ketostix measure acetoacetate, correct? Is B-OHB level a more reliable measure to determine one is in ketosis? Why?

    • 1. I don’t know. Would need to know a lot more to even hazard a good guess.
      2. Not sure, but timing of consumption and activity level may have something to do with it. Nuts don’t stimulate much insulin in most people, so that may play some role.
      3. Blood B-OHB is the gold standard for measuring ketosis.

  • Mark

    Peter- is there a “best” alcohol in your opinion for keto? I’ve had this argument (over drinks) with many friends and so many opinions– beer vs. red+white wine vs. hard alcohol incl. whiskey vs. vodka vs. tequila etc. Any advice for social drinkers?

    • No idea.

    • David

      Hard liquor is the best by far. Between those, there is very little difference (save for those that have sugar in them, like rum or flavored vodkas, which should obviously be avoided). Wine is the next best, followed by bread in a bottle: beer.

  • Espider

    Hi Peter,
    I’ve been on a keto diet for 6 months now and it’s the best decision I made in my life. I recently started weight training and I want to take the max out of both worlds. Can I add for example around 100g of carbs before my workout to be used as energy for the workout and keep my carbs as minimum as possible in my non-training days ? Do you think this way I can have maximum performance and still keep the healthy benefits of staying low-carb ? And will this ruin my keto-adaptation ?
    I wouldn’t think about carbs to enhance my performance but I’m very skinny and I have to gain weight. Body fat is not an issue even with my prevoius high carb diet my body fat was veery low.

    • It’s possible, though I don’t consider myself an expert in this particular issue of maximizing hypertrophy in ketosis. Give it a shot and track all the data you can. You will need to closely monitor B-OHB levels to know if you’re “in” or “out.” See the posts (2) on the interplay of exercise and ketosis.

  • seth

    I miss your posts……..anyway .I was wondering what your thoughts as are on if excluding carbs from your diet has any negative effects on Testosterone. LH, FSH etc and other hormones compared to including them? Being Ultra low carb vs including some. Usually the anti-lowcarbers harp on ketogenic diets causing adrenal fatigue and extreme cortisol levels and all types of things.. what are your thoughts or guess for someone trying to optimize their hormones and build their physique?

    • Many people actually experience the opposite, especially if transitioning from a “standard crappy American diet.” LH and FSH in a snapshot don’t tell us much, free certainly free testosterone does.

  • AJ

    Not meaning to revive an older blog posting, but Dr Attia, do you know of any synergistic role of testosterone and hgh on activating abdominal HSL in humans (in order to decrease visceral adiposity)? I think this was true in mouse studies, not sure if was validated in humans. Of course, I get the science of firstly reducing circulating insulin to keep LPL levels low and thereby hopefully increasing HSL and in turn mobilize abdominal fat… just wanted to know if the actual physiology of hgh in this capacity was known in humans ….

    • Testosterone increases factors that favor lipolysis. I don’t recall off the top of my head if this is primarily mediated by HSL or LPL or some other pathway.

  • Gastonluque

    Hello petter, I am charmed with reading his blog .. I want to know that he thinks of the civilization kitava.? They feed in 70 % of carbohydrates

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