Saturated Fat REDUCES risk of stroke and heart disease

As readers of the book know, we regard saturated and monounsaturated fats as the only macronutrients that are safe in unlimited doses. Other macronutrients become toxic above certain levels: glucose above 600 calories per day, protein above about 600 calories, and polyunsaturated fats above 100 calories. We recommend that 60% of calories or more be obtained from saturated and monounsaturated fats.

Since eating more saturated and monounsaturated fats is likely to displace toxic nutrients from the diet, in the general population we would expect higher saturated and monounsaturated fat intake to reduce disease rates.

Despite the prejudice the medical profession has long held against saturated fats, there was never real evidence against them. But after many decades of demonization, high quality studies are now showing saturated fat to be health-improving – just as we would expect.

A New Study from Japan

Via Dr. Briffa and Dr. Stephan Guyenet comes word of a new study from Japan.

This study followed 58,453 Japanese adults, aged 40 to 79 at the start of the study, for 14.1 years. [1] The study found that higher saturated fat intake was associated with:

  • A 31% reduction in mortality from stroke
  • An 18% reduction in mortality from cardiovascular disease

It was only earlier this year that a systematic review of the literature found that “there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.” [2] In a few decades the reviews will probably have to go further: there will be significant evidence that dietary saturated fat is protective against CHD and CVD.


[1] Yamagishi K et al. Dietary intake of saturated fatty acids and mortality from cardiovascular disease in Japanese: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Study. Am J Clin Nutr. 2010 Aug 4. [Epub ahead of print]

[2] Siri-Tarino PW et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr. 2010 Mar;91(3):535-46.

Leave a comment ?


  1. I’m curious as to the comment that protein is toxic above about 600 calories. For an active 200# person trying to build muscle it’s common to consume about 800 calories and some advocate up to 1600 calories of protein. I’m in the 800 calorie camp as that level allows more fat consumption. What is the concern above 600 calories?


  2. Hi Stan,

    Well, you will find different views about where significant toxicity begins. I acknowledge that protein toxicity at 800 calories/day is small. (1600 calories is very dangerous.) I just don’t see evidence for benefits, even for athletes, from exceeding 600 calories/day.

    For routine function of the body, 200 calories is sufficient, and only a slight additional amount is needed to supply sufficient protein to add muscle. However, there are hormonal benefits for muscle building from maintaining high levels of certain amino acids, especially the ketogenic and branched chain amino acids, e.g. leucine. So for athletes a plausible approach would be about 300 calories protein from meat and 300 calories from whey protein, which is rich in the muscle building amino acids.

    All this assumes that glucose is intake is adequate; for athletes we would suggest about 500 calories per day plus 50-100 calories per hour of intense training. If glucose is restricted, more protein may be needed for gluconeogenesis.

    While the scientific literature suggests an absence of benefit from high levels of protein, many athletes and bodybuilders believe that adding muscle is easier with higher levels. I would suggest you adopt the diet and then self-experiment to see if that is true for you, comparing protein intakes of 400, 600, and 800 calories per day. You might find surprisingly little difference.

    Apart from its effects on muscle, we tend to favor low protein intake because it assists intracellular immunity and promotes longevity. So you have to balance your goals.

    By the way, I gain muscle on 200 protein calories a day, working out twice a week for half an hour. So, while more protein might let me gain muscle faster, low protein intake is not a bar to muscle growth. In general, our diet is muscle-friendly.

  3. Hey everyone,
    A little off topic but I was wondering why macro-nutrient levels are given as an absolute number of calories instead of a percentage of total calories?

    For example, a 5’0″ 110 lbs female will have much different protein requirements than a 6’5″ 250 lbs male, why should they eat the same amount of protein.

  4. Hi Nick,

    An excellent question.

    It’s a little tricky to make prescriptions. We also often say 20% carb / 15% protein / 65% fat which for a 2000 calorie diet (a sedentary slender person) would be 400 carb calories / 300 protein / 1300 fat.

    Protein needs tend to track lean body mass. So the low end of the protein range is perhaps 2/3 as much for women as for men, and maybe the optimum is too. However, the high end probably doesn’t differ much for men and women. Since our protein range is pretty broad, we think a 200 to 600 calorie range will be pretty good for both men and women.

    Giving the calorie ranges is more accurate on low-calorie diets. If you wanted to eat a restricted 1,000 calorie diet for weight loss, which we DON’T recommend, the safest might be still 400 carb calories / 300 protein calories / 300 fat calories.

    On high calorie diets, for very active athletes for instance, protein needs don’t go up, so the <600 protein calorie recommendation still stands. Glucose needs go up, but only at most by about 100 calories per hour of training. Fat needs go up. So on very high calorie athletic regimens (unless we're talking offensive lineman who you want to be fat), fat will tend to rise toward 70%+ of the diet, carbs to shrink a bit to 15%, and protein toward 10%.

    Overall, I think calorie ranges and our older 20%/15%/65% prescription are both pretty accurate through a 2,000 calorie/day to 4,000 calorie/day energy budget, which is what most people consume. The calorie ranges work better on restricted diets, and on very high calorie diets the optimum is in the middle between the two.

    One twist is that for some diseases we recommend a ketogenic diet, and that has more rigorous requirements which are best expressed in terms of calories -- 200 calories glucose, 400 calories protein, 1500 calories coconut oil. So calorie ranges work best here.

    Over time I've migrated to the view that calorie ranges will be more helpful to most readers, and so that's what I now use.

  5. Aaron Ashmann (halotek)

    Quick question — I know the saturated fat question has been beaten to death — but what about questioning how your body feels after you eat it.

    I’m only 30 and have a muscular build, but if i eat 30+grams fat in the form of butter, coconut oil, or tallow, and almost always feel like i get a slight tightness in my chest and or slight numbing sensation down my arms. The effect seems to pass over about 1.5 hrs. And I seem to feel ok after 2hrs post meal.

    How do I know I’m not damaging myself by continuing to eat more fat (from the post prandial trig surge?). The research seems to clearly support high fat intake, but I never seem to get these types of problems with high carbohyrate meals or even high saturated fat meals WITH carbs.

    Do you know of any way to counter the contraction effect saturated fat may be having on my arteries when trigs go sky high after a high fat meal? Maybe thats why you really have to keep to 1-2 meals a day. Suggestions please. Keto adaption did not work to keep the side effects away — and the effect was still there after months of low carb eating.

    I’ve tried tea and other foods that I felt would promote vasodilation to no avail. I almost feel like I’m stuck keeping fat to a lower intake.

  6. Hmmm, I’ve never heard of that phenomenon.

    Can you give us more information? Any history of metabolic syndrome or being overweight? Any other diseases? What is your regular diet like?

    What happens on a 30 g / 2 tbsp dose of fish oil? Of olive oil? These are low in saturated fat. It would help to know if they reproduce the problem.

    Why do you think you have “contraction” of arteries? The literature is mixed, but reports of dilation as an effect of saturated fat meals, e.g., seem to have the upper hand.

    What happens if you take arginine (for nitric oxide vasodilation)? Does it relieve any symptoms of the fat meal? Does it reproduce the symptoms on a carb meal?

    Do you have any issues with hypoglycemia / low blood sugar? You might try getting a blood glucose test kit and pricking yourself every 15 minutes after a sat fat meal and a sat fat with minimal carb meal — just enough carb to get rid of the feeling. Is blood glucose lower on the sat fat meal?

    Does exercise relieve symptoms or exacerbate them?

    Do you have to eat the carbs with the fat, or is it OK to eat them at a different time of day? Is this an artifact of a zero carb diet, which we don’t recommend?

    I’m puzzled. If anyone has experienced or heard of something similar, please comment.

  7. No history og metabolic syndrome — bg is usually 85 fasting, trigs 71. HDL 61 — LDL 131.

    My regular diet is something like 20% protein 40% carbs 40% fat. But i have received the symptoms i’ve mentioned after weeks of a diet of 15% protein, 60% fat, 25% carbs.

    I received the types of symptoms i mention when I eat a meal of about 30 grams of carbs with 30+grams of saturated fat. I know fish oil does not cause the same sensation, because I have tried a massive amount before (but it did give me mania). Flaxseed oil did not give me the above symptoms, but I stoped it anyway because I felt kinda speedy from it. Olive oil gives me a little of the same effect as above — but not as much as coconut oil or butter.

    Exercise seemt to make the sensation fade away faster.

    How do I know if my body is just respondingly badly to the post-prandial trig surge — I know that is a stressful event to the body.

  8. One possibility, Aaron, may be a surplus of adenosine.

    See symptoms of adenosine excess:

    They include chest pressure and tingling of the arms.

    Then the question would be why you’re getting an adenosine excess. A ketogenic diet can raise adenosine,, but your diet doesn’t seem very ketogenic.

    You might try some supplements to see if they help:
    Vitamin C, 2 g/day, for carnitine & fat transport; Creatine, for phosphate donation to adenosine; maybe ribose too.

    I’m still highly puzzled, but I wouldn’t be surprised if there is some nutritional deficiency involved.

  9. I should clarify that its a slight numb sensation in hands and arms (slight) — and a slight tightness in chest (almost like I am not relaxed, unlike the effect carbs have). The effect is more noticeable if i’ve been on a reduced carb diet (50-100g of carbs)

    Vitamin C in supplement form has almost always made me feel a little ill ( I eat a ton of veggies though so I don’t think I have a defeciency). Carnitine – especially propionyl-l carnitine made me feel good — but after 2 weeks of continous supplementation — I felt like I had adrenal burnout — not to mention I seem to get a slight Hemorrhoid (bulge), and slight headaches). The same result occured in the past when I took a stimulant, intermittantly fasted (warrior diet), or continued on a multiple weeks of <40 carbs a day diet. All probably contributed to increases in dopamine, that made it hard to sleep and made me feel wired. Curiously, large amounts of fish oil/ flaxseed oil give me mania and make it hard to sleep (after taking them for a few nights at larger doses). Carbs at near bedtime really relax me, but give me uneasy sleep — whereas low carb just didn't allow me to sleep.

    I don't consume creatine because my creatinine levels are just just borderline high (which may be from my pretty decent muscle mass).

    I always feel better from a little exercise – but over 30 minutes of exercise usually leaves me feeling like i did too much (if I do it for days). I usually walk about 5 miles a day regardless.

    My typical diet usually consists of tuna (sardines), grass fed meat, 2 oz of olive oil, 300 grams of fruit, about 1.5 lbs of veggies. I also usually have a small treat everyday like a cupcake of some sort. I also consume 400-600 calories of white rice or 1-2lbs of potatoes/sweet potatoes.

    My only supplements are D3, K2, iodine, mag (200 day). Occasionally a good multivitamin or Coq10.

  10. Hi Aaron –

    Your “typical” diet sounds nearly perfect in terms of macronutrients — it’s within our optimal ranges. Am I right that you don’t get the numbness or tightness on this diet?

    Supplements are great too. We also recommend selenium, copper, and chromium.

    Your diet is very high in fiber. So you probably have a big gut bacterial population and high endotoxin levels. That suggests another possibility. Lipopolysaccharide is fat-soluble and when you eat fat it carries endotoxins from the gut into the body. This excites an immune response. So an unusually large fat intake may trigger an endotoxemia. Peter at Hyperlipid talked about this:

    Saturated fat, especially coconut oil, carries more into the liver, so that may account for the differences in fat type.

    You might try cutting fiber for a while. Drop the veggies, stick to white rice over potatoes for a few weeks. Your bacterial population will decrease. Then try the high fat meal and see if your symptoms are gone.

    See the fiber discussion in this post: It might be possible to get too much fiber.

  11. Paul,

    Totally unrelated with this post, but related to your blog :). I don’t know if you discuss this in your book (I’m waiting for the printed version) or if you plan to make a post about: iron overload and infections.

    Since we are on a meat/organ diet, iron became a concern, specially for men and women post-menopause.

    This is not a very discussed topic, but have been brought to my attention by Michael Eades.

    There is a very good book on iron overload by E. D. Weinberg Ph.D., “Exposing the Hidden Dangers of Iron”.

    Blood donation should be a part of any healthy plan!

  12. Hi Mario,

    It’s a good point and no we don’t discuss it in the final version of the book either. We do say that iron should be taken as a supplement only to prevent deficiency, never in excess.

    Iron is an extremely important nutrient for bacteria. It not only promotes biofilms, it is essential for their metabolism. Iron restriction makes infections much less likely.

    That said, iron is also essential for human health. Iron is an ingredient in important enzymes like catalase (a mitochondrial antioxidant) and myeloperoxidase (immune-fighting enzyme). Of course, everyone knows about hemoglobin and iron-deficiency anemia.

    I will have to look up that book and also search the literature to see if there are any studies comparing disease rates among blood donors and non-blood donors. If I can find solid data, that would make a good blog post.

    Best, Paul

  13. This is a great study!!! I agree that saturated fats had gone from been the demon macronutrient to neutral. As more studies like this come out it will start to be treated as a health food. What a DIFFERENT world that will be. Of course everyone will deny that it was THEM that was against fats.

  14. Re Aaron’s Post
    I experienced something similar but not as pronounced. A little background for context: I came to LC from the opposite direction ie high carb/frequent meal experiment (my doc’s idea) which clearly made my periodontal disease worse and so I went progressively in the other direction as an experiment and eventually stumbled onto the LC diet culture. By normal measures I was quite healthy, normal blood panel, normal FBS, FSH ( 1.2-1.8 over last 6 years), not overweight and physically active, but my BP ticked up to 135/90 in one year and hence the reason to experiment with diet. So my profile seems quite different from some bloggers here.
    Results of the LC diet were mostly positive, however there were also some anomalous results which I cannot explain (I have no health qualifications). Eating small amounts of carbs (~50g/day glucose) produced a palpable heart beat so that sleeping on the left side was uncomfortable. Eating a larger than normal amount of fat at one meal produced a palpable heart beat for a short time but not as severe as Aaron’s. As well, dairy products and cheese specifically resulted in joint aches (tendons and ligaments). If I was averse to dairy on high carb diet, the symptoms were not apparent to me. Also BM regularity was becoming a problem and a concern. So I have increased my glucose to 400-500cal/day and I balance the FPC portions at each meal. The negative symptoms are slowly receding. Overall the diet seems beneficial, I feel better and the food tastes great. My gums have improved, BP is normal (typ 105/65) and there appear to be many improved biomarkers. But I have to admit that my experiments are not conclusive (yet) because maybe not enough time hast elapsed, I mixed changes eg started high doseVit-D/K2 supplements and lower carbs at the same time, and perhaps there are some underlying chronic condition which is unaccounted. I hope this longwinded post is in some way useful to others I would like to hear experiences of others’.
    Paul, I very much appreciate the effort and knowledge you bring to this blog and particularly the balanced view of the subject.

  15. Morris, I did not feel like my heart was beating weird — just a fullness feeling in my chest and slight numbness in my arms.

    The effects are most noticed when i have any of the following meals: large amounts of bacon, large amounts of heavy cream, large amounts of butter, large amounts of coconut oil. Especially if I eat them by themselves. Combining them with large amounts of fish oil or veggies seems to blunt the response but I don’t trust that nessesarily.

    Paul, I don’t think plant toxins are to blame for my symptoms, or I wouldn’t have them when I have consumed animal products on their own. Not to mention, most people would have problems in nut oils and olive oils if that were the case because of all the plant compounds.

    I’m a little puzzed about your fiber comment. I wouldn’t say my fiber intake is too high — and I don’t have any bloating from it’s intake. I trust butyric acid from my own bacteria more then from consumption of a completed fat (like butter). There seems to be many more studdies showing benefits from a healthy flora than one that is depleted by a diet higher in fat and lower in fiber (which decrases flora content) (even if i believe that a higher fat diet is potentially better for mitochondrial function). You seem to suggest that lower levels of all bacteria are preferable to one that is high in good bacteria and moderate in bad bacteria (ala peter at hyperlipid). That would seem to really knock any kind of supposed benefit from probiotics. Once good bacteria levels are lowered — I still wonder how we can keep bad bacteria in check– even if our fiber and fructose levels are lowered.

  16. Hi Aaron,

    A few clarifications:

    (a) I didn’t suggest that your symptoms might be due to plant toxins, though I suppose we can’t rule that out, but rather to bacterial toxins.
    (b) The immune reaction I’m speaking of needn’t cause bloating. I’m thinking of endotoxins from probiotic bacteria (so the local immune response in the gut is suppressed) that are carried by chylomicrons throughout the body. So the immune response is not local in the gut, but systemic.
    (c) Probiotics have benefits when they replace pathogenic bacteria with probiotic species. Since I’m working from the assumption that your species are already probiotic, probiotic supplements should be neutral/inconsequential for you.
    (d) Of course, if we allow for pathogenic infections that would add another layer of complexity and another possible set of explanations. But I think with so little evidence to go on, we should stick to non-infectious explanations if we can.
    (e) Re your concern, you don’t need a lot of probiotic bacteria to keep gut pathogens in check if your immune system and gut are healthy and properly functioning. The total population of bacteria will rise or fall with fiber consumption. Babies’ guts are healthiest on a limited gut flora fed by no fiber at all, just a few oligosaccharides and glycoproteins. We don’t really know what the optimal amount of fiber / gut bacterial population is. Studies showing benefits from high fiber intake are confounded by the fact that health-conscious people tend to eat more fiber.
    (f) Over long periods of time, the immune system and gut adjust to control the level of endotoxin entry into the body. Low endotoxin levels are dangerous (promoting pathogenic infections, see Peter’s post) as are high levels (causing inflammation/toxicity).
    (g) Butyrate from butter is just as good as butyrate from gut bacteria. It’s the same compound.

    It seems obvious from basic biochemistry that endotoxin levels entering the body will be highest on high-fiber high-fat diets, and highest of all when transitioning from a high-fiber high-carb diet because the gut and immune system will not yet have adjusted to the extra endotoxins carried in by the new higher fat intake.

    If bacterial endotoxins are at fault, you should notice elevated body temperature when you eat the high fat meals. Have you noticed that?

    As I say, this is just a hypothesis and I wouldn’t put much weight on it at this point. I just think it would be interesting if you did the experiment with lowering fiber to see if you became more tolerant of a high-fat diet. Such an experiment would help us calibrate optimal fiber consumption on high-fat low-carb diets — something we have very little knowledge of at this point.

  17. Morris – Thanks for letting us know your symptoms. Hopefully over time many people will share their stories and we can learn from each other.

    It sounds like you have some dairy protein (casein) sensitivity. Since we recommend 400 glucose calories as optimal for most people, you’re very close to our optimum. We think nearly everyone will do OK on 200 glucose calories, but maybe you’re one of those who needs more. Many infections consume extra glucose, so your chronic underlying conditions might account for the difference.

    I would try coconut oil to see if it enables you to reduce carb intake a little.

    Best, Paul

  18. I’ve always noticed my immume response to be stronger on a high carb diet than a low carb one. My body temperature does seem to increase while eating a lot of fat, but I always seemed to attribute that to the fact that I fasted before meals and once fat enterted my system – processes of my metabolism would also be creating the extra heat.

    If I eat a lot of ghee — where am i going to be getting B vitamins from (I have never done well on those supplements) usually I get them from the veggies — plus i wouldn’t be eating a lot of animal protein because i usually keep it to 6oz or less a day.

    I have noticed that I do get a bit gassy on probitics — especially if combined with fructose. I feel like bacteria wise, my stomach is in good shape.

    ALso, are you saying that any remnant beneficial bacteria would be sufficient if your diet is high in fat with a little bit of plant fiber (as you have prescribed)?

    I’d be interested in trying your experiment — but i have always felt the worst when keeping plant foods low and animal products high (even if it is low protein, high fat)

  19. Hi Aaron,

    The immune response to extracellular pathogens begins with glucose, so definitely a too-low-carb diet may impair immunity.

    Body temperature is complicated, very low-carb diets tend to produce high body temperature so it’s not clear whether the cause is endotoxin/immune-related or mitochondrial uncoupling proteins turning on to aid in disposal of excess fat. But if your body temperature didn’t rise, that would argue against endotoxins.

    6 oz meat is OK, that’s about our low limit for protein. If you mean 6 oz pure protein that’s at the high end of our protein range.

    B-vitamins — what’s wrong with a multivitamin and the diet of our book? That should provide about triple the RDA of most B-vitamins.

    Fructose is not a good idea.

    Yes, I am saying that on our diet, even with no vegetables and just the fiber contained in 300 calories safe starches and 100 calories fruit, you’ll maintain sufficient probiotic bacteria for good intestinal health. That’ll be roughly a pound of plant food per day, which is sufficient. An additional half-pound of vegetables would be fine.

    So you’d be at about 1.5 lb plants, 0.5 lb meat, plus some oils, for a 3:1 plant:animal food ratio.

  20. I agree with your first statement.

    You could be right about increases in body temperature from endotoxins (because my rise in body temperature usually only lasts about an hour) — but I still think it’s mitochondrial uncoupling.

    I usually eat about 4 oz of fish and 4 oz of chicken — just about the perfect amount for protein. But for longevity reasons, I like to eat less sometimes.

    I’ve always felt crappy on a multivitamin — dull headaches and the like — so many types of nutrients tend to give me dull headaches (when i usually never have headaches, i am very cautious of what i take. And because I usually get dull headaches from pototes and sweet potatoes — its hard for me to find a starch substitute that has the b vitamins i need without a multi. I guess fortified white rice could be a choice (and I already eat it). I won’t do brown rice.

    1.5lb plants is probably 300 calores starch and probably 100 calories non-starchy. = 400 calories

    0.5lb meat is probably ~350 calories with the fish and chicken I eat.

    with 2oz of olive oil on my salad at lunch for around ~240 calories I’d still need to eat about 900-1300 calories of ghee or other fats to make my diet complete- and at that point, I’d still be worrying about water soluble vitamins — and potassium because I really don’t like taking a multi. (of course I take most of the 8 micro nutrients you recommend except for selenium because I eat a lot of seafood)

  21. Hi Aaron,

    Yes, we try to eat fatty meats like salmon or ribeye steak to get more fatty nutrients, e.g. phospholipids. We don’t eat lean meats often, and usually add egg yolks.

    You might find egg yolks a good fat source, 6 egg yolks a day would provide about a third of the RDA of many B vitamins in 300 calories.

    I think in general your diet is very good. It’s a little puzzling that even little things like a multivitamin give you such trouble.

  22. As a side note, I really appreciate your fine tuning of the applications laid out in your book for me — it’s a big help! I’ve been following a lot of good blogs for years now — your ideas seem to be just about on par for about everything I believe. I’m still not convinced we need to go as low carb as you lay out — but I am also wary of the type of carb source given antinutrients in plant foods — and the lack of vitamins from a source of carbs like white rice. Not to mention my apparent slight headaches and joint aches from root vegetables like sweet potoates and potatoes ( I also seem to get a slight flare up of tendonitis in my heels when I eat them — which passes within a few hours). The most comical thing of all is that I seem to be fine when I eat oatmeal or barley — yet I stay away from them because of the gluten. So i’m searching for an alternative to potatoes/sweet potatoes/taro for a source of carbs that is gluten free and not (white rice). buckwheat is neutral — quinoa and amaranth gives me dull headaches.

    I know it sounds like another whopper — but I know for a fact that i’m allergic to egg yolks and dairy (except for butter/ghee). I get increased mucus/increase in body temp/scratchy throat/ and general malaise. Otherwise, I would pound egg yolks every morning like I used to.

    Red meat also gives me a scratchy throat and slight tightness feeling in my chest (but I still eat it on occasion) — fish and chicken do not do this so I usually feel comfortable eating them.

    Lastly, like I mentioned in one of the above posts — I get really scared i’m increasing my sympathetic nervous system if I decrease carbs too low, I feel like I can’t sleep, have teeth grinding, and usually get slight hemorrhoidal bulges (even with regular bowel movements. Even 40% carbs at times feels too low — but I stick it out. Which is why I was glad to see a blogger like Matt Stone out there (because he has had other people experience what most bloggers had not covered before)

    I really wish I could find a multivitamin I like. I’ve always taken very high quality brands — its possible centrum wouldn’t affect me much because of its lower absorbtion vs the really high quality brands (even if you believe centrum would be good enough!). I agree with you that for critical micronutrients it’s good to supplement — but for the rest, I feel like I should get them from food — nature still knows best with the ratios for b-vitamins that would be naturally present in foods.

    So my comfort foods are fish, chicken, veggies,fruit, nuts (which dont give physical problems, but give me pimples). I probably need to expand my intake of low anti-nutrient veggies to get more nutrition without the toxins.

  23. Paul
    In response to Aaron, you wrote “If bacterial endotoxins are at fault, you should notice elevated body temperature when you eat the high fat meals. Have you noticed that?” Applying this to my case ie some problems with low (200cal/d) carb diet, I experienced a body temperature rise from normal 36.7 to 38.3 deg C in minutes after eating 2 squares (280kcal) of pure chocolate; this was during the very LC period. A repeat experiment the next day did not raise my temperature, adaptation? Please elucidate why ingested fat causes body temperature to increase ie become more inflamed and connection to endotoxins. Does consuming fat somehow increase gut permeability? in unhealthy gut only? My questions are probably ill-posed and your patience in appreciated.
    I should have stated in my previous post that I also added a lot of vegetables ie increased fibre and together with higher glucose intake the negative symptoms are declining after 2 weeks. Also I should have stated that negative symptoms began 10-12 weeks after start of LC diet.Thanks again.

  24. Hi Morris – No, fat doesn’t increase gut permeability. It just carries fat-soluble proteins like endotoxins with it.

    Ingested fat doesn’t cause more inflammation/endotoxins if it is eaten regularly. It’s unusually high fat intake, much higher than the normal diet, that does it. The immune system will regulate bacterial populations to keep endotoxin flux at a controlled level, neither too high nor too low. Antibiotics are problematic in part because they reduce endotoxin flux too much.

    I don’t know why chocolate would raise your temperature one day but not the next.

    Since your 400 calorie carb intake now is optimal, I wouldn’t worry too much that you had trouble on very low carb. There are various ways that can cause trouble. After 10-12 weeks, you could have vitamin C deficiencies and other common slow-developing very low carb problems.

  25. Aaron – I’m very sorry that so many foods give you trouble. It seems very difficult to construct a “perfect” diet for you, but maybe a “very good” one is good enough.

    I wouldn’t worry too much about 40% carbs, given all the other troubles, if they’re from safe starches. We don’t know for sure that glucose toxicity is much of an issue, if there are no PUFA toxins, fructose, or wheat/grain/legume toxins in the diet. In any case it might take decades for glucose toxicity to do significant harm, while these other things seem harmful quickly.

    Since some of your symptoms (teeth grinding, hemorrhoids, cognitive symptoms) are common effects of infections, I think you should seriously consider experimenting with an antibiotic and see what happens. If it’s affecting a pathogen, you may notice good or bad effects; if it’s not, you’ll probably notice no effect. It may be a shot in the dark but it could have a big payoff if it works.

  26. there are definitely benefits to exceeding 600 calories/day of protein. first of all, it’s ridiculous to make protein recommendations that aren’t based off of weight, because people with more LBM need more protein. i weigh 235 lb, so 150 grams of protein is not enough for me, especially because i am very physically active and lift lots of weights. the problem is you are looking at how much we need to survive, not how much we need to maximize physiological adaptations to exercise. read berardi’s article “Protein Prejudice” for more info I can provide you with numerous references that show that protein intakes close to 1 gram per lb of body weight are optimal to maximize physiological adaptation to exercise if you are interested. Clearly for heavy individuals, 600 calories/day of protein is nowhere near enough

    also, i dont understand how you can make blatant statements like “more than 100 calories of polyunsaturated fats are dangerous” without even knowing someone’s antioxidant status. i eat at least 10 servings of fruits and vegetables per day, often 15 or more. shouldn’t i be able to handle a lot more than 100 calories of polyunsaturated fats? i consume large amounts of flax seed and fish oil, but because i consume so many fruits and vegetables, why would i have any problem with my huge polyunsaturated fat consumption?

  27. Hi Zach,

    PUFA: Antioxidants don’t prevent PUFA toxicity and the fructose in fruit exacerbates it. There’s plenty of evidence for PUFA toxicity, we spend 31 pages in the book giving a thorough discussion.

    Protein: The T-nation link you give actually offers an excellent overview of protein needs, and is consistent with our survey of the literature. (Thank you for the link!)

    As he notes, there’s little evidence of gross protein need above a relatively low level (0.65-0.8 g/kg).

    As we say in the book, there may be hormonal benefits from additional intake of protein to increase certain ketogenic and branched-chain amino acids, but overall protein needs remain low. The other reason protein needs may be elevated is if they are being consumed for energy. On low-carb diets, up to 400 calories/day protein can be used for energy. However, we consider this undesirable, for the most part, and would try to eat enough starchy carbs to reduce protein utilization for energy to 100 calories/day.

    Getting back to your link, the main problem with his argument is that the “benefits” he lists from higher protein consumption are NOT benefits to anyone on the Perfect Health Diet. For example, displacing carbs from the diet may reduce cardiovascular risk if you’re starting from carbs as 63% of the diet, but not if you’re starting from carbs as 20% of the diet.

    The main reason not to expect any benefits from very high protein consumption is that the body CANNOT utilize more than about 600 protein calories per day (a bit more if carbs are severely restricted), and any excess has to be excreted in a manner that places a toxic burden on the body and kidneys.

    Body size is not a huge factor, because your higher body mass also means that the supply of protein from muscle catabolism is higher. Catabolized protein is efficiently recycled. Since 20 calories/day protein is enough to add 26 lb muscle per year, muscle growth isn’t a major contributor to protein needs either.

    I will do some blog posts on optimal protein in the future. I do respect the claims of many bodybuilders that they benefit from high protein intake, but the literature doesn’t support those claims, and I would like to do a deeper investigation to see if there’s something I’ve missed. But your link suggests there isn’t.

    Thanks for the comment! It raises interesting points.

  28. Paul, If you take a low dose anti-biotic, you don’t need to take probiotics (and if you do, is there one you suggest)? I’m highly considering doing it just to make sure I clear up any lingering infections.

  29. Hi Paul,

    How do eating nuts, such as Brazil nuts for selenium, and maintaining low omega-6 co-exist? Are not nuts high in omega-6?



    • Hi Robert,

      Yes, but … 2-3 Brazil nuts/day provides 200-300 mcg selenium which is our target … and contain 2-3 g (18-27 calories) omega-6. We recommend trying to keep PUFA to around 100 calories per day, which will be primarily omega-6 linoleic acid.

      So it’s fine to eat some nuts, as long as you’re not making whole meals out of them. And they can be a convenient way to get certain nutrients.

      Hi Aaron,

      Well, I would take probiotics while on antibiotics. You want to keep gut bacterial populations up, in order to maintain proper immune surveillance of the intestine. I think any probiotic with a diversity of species and high counts is fine. You’re not really looking to supply needed species, just increase bacterial numbers. A fecal transplant would be needed to replenish species, which you might consider if the antibiotics go on for a long time.

      Since you don’t know that you have an infection that would respond to antibiotics, you might want to start with a standard dose in order to more clearly see if there is an effect. Then if you’re persuaded there’s a bacterial infection then a low-dose strategy might be in order. Discuss it with your doctor.

      If you do start antibiotics, it would be interesting to repeat the fatty meal experiment a week into the antibiotics to see if the problem has gone away. That would tell whether it’s an endotoxin issue.

  30. Hi Paul,

    About keeping PUFA to around 100 calories a day, does the limitation refer to Omega-6 only, with no limit on Omega-3? Or is the 100 calorie limit comprised of the sum of Omega-6 and Omega-3? About what should be the ratio between those two Omegas?



    • Well, we recommend eating about 1 lb salmon, sardines, or other oily marine fish per week. That provides about 12-15 g = 100-130 calorie/week omega-3 or 15-20 calories per day. Whether you eat 80 or 100 calories omega-6 per day doesn’t much matter. It will be almost all linoleic acid. The key is that you get long-chain omega-3 and you keep down the total omega-6 to 100 calories or less, preferably less. Most linoleic acid isn’t converted to long-chain omega-6 so this produces a good tissue ratio of long omega-3 to long omega-6 which is what we are aiming for.

  31. Hi Paul,

    Sorry to bother you with calculations. At the moment we’re looking at 5:1 omega 6 to omega 3 based on your recommendations above. What you say is interesting although it goes against what I’ve read in the paleo blogosphere in the last couple of years; I agree that we should try to get our omega 3 from oily fish, although not everybody can, especially people on the continent where tinned sardines or mackerels have never been consumed on a regular basis. Could you give a reference about linoleic acid conversion to long chain omega 6? Will it be in your book? It seems to me that 10 grams omega 6 is too much. If it comes in the form of nuts maybe it’s not so problematic.(if they’re fresh)
    If I’m here I will ask you another thing.
    For the last 2 years I haven’t eaten almost any starches (no bread, pasta, rice and potatoes) only vegetables and some fruit . You are recommending 100 grams of starch coming from rice or potatoes. That is 500 grams of potatoes or about 300 grams of rice. It seems a huge amount and combined with the 100 grams of fat will I not put weight on?
    Thank you.

    • Hi simona,

      Yes, the PUFA issue is treated thoroughly in the book with references. It’s complicated because every fatty acid is treated differently in the body, so it’s misleading to sum up all omega-6s together and all omega-3s together as if they were all the same.

      Here is a synopsis:

      We want to achieve two things, avoiding toxic levels of PUFA and achieving the optimal tissue ratio of long omega-6 to long omega-3.

      Omega-6 PUFA toxicity probably begins above about 4% of calories and total PUFA toxicity above about 5% of calories. So, on a 2000 calorie diet the omega-6 limit would be 80 calories/day; on a 2500 calorie diet 100 calories/day.

      The average American gets about 340 calories omega-6 PUFA per day. So if you cut omega-6 down to 100 calories, you’re way ahead of the average American and in pretty good shape.

      The important omega-6 to omega-3 ratio for health is the ratio in cell membranes — the “tissue ratio” — of the long PUFA, 20-carbons or more. The 18-carbon PUFA, linoleic acid and alpha-linolenic acid, are comparatively innocuous when in cell membranes, although they can be harmful in other places.

      We’re advising eating long-chain omega-3s directly from salmon or sardines, but the omega-6s in the diet come almost entirely from the shorter linoleic acid, and only a small fraction are converted to long omega-6s like arachidonic acid. So you can have a 5:1 ratio in diet and have a perfect (1:3) long omega-6 to long omega-3 tissue ratio.

      On the other hand, if you got omega-3 from ALA, the short-chain omega-3, you would need a much higher dietary omega-3 intake to optimize tissue ratios.

      In practice, with so much linoleic acid in supermarket foods, it’s hard to get omega-6 much below 3% of calories even if you’re very rigorous. The healthiest way to balance omega-6 to omega-3 in tissues is with a small quantity of long omega-3s rather than a large quantity of ALA, so that is why we recommend oily fish as the source.

      Re your other question, will you gain weight if you eat 400 calories starch, if you have a healthy metabolism the answer is no, definitely not. If you have a damaged metabolism (diabetes, history of obesity) then you might. If so, then you need to try the “ketogenic diet” variant. In the final version of the book we have a “Step Four” for healing from various diseases and we talk about how to implement that.

      But I would definitely eat some starch. Even in the ketogenic diet we recommend at least 200 calories per day. This is much safer. I’ll do some blog posts on this matter of low-carb safety soon.

  32. Thank you.
    On the LC diet I lost 36 kg in one year and a half, so I might have a ‘history of obesity’. I have been doing IF for a while now and I got used to eating 2 bigger meals a day. Sometimes I would have a 24 hour fast too.
    Increasing my starch (potatoes or rice) seems difficult for me as I rarely have a half of a small potato with my dinner, generally I have non starchy vegetables around 200 kcal or more and berries. I haven’t eaten a full apple in years.
    I’m trying to see if I can improve my diet as I still have some unexplained symptoms (chronic gum disease, hair loss and acne, high LDL).
    I didn’t know about the reduced conversion to AA. I am trying to avoid all seed oils, only cook with olive oil, butter, ghee, but I know there is still a lot of LA overall (from pork, chicken). It seems I shouldn’t worry too much about it.
    Hope I can buy your book.

  33. Hi Simona,

    I’ll do some posts on obesity soon.

    I think you would really benefit by adding in some starches. It is mainly a safety concern. A few hundred calories of starches won’t cause you to gain weight, if they are substituting for protein or fat, and they will probably reduce your appetite and make fasting even easier.

    Chronic gum disease can be caused by vitamin C deficiency, which is induced on zero-carb diets. Hair loss is commonly the result of hypothyroidism. Have you checked out your thyroid hormone levels?

    Re the omega-6s, we try to eat low-omega-6 meats like salmon and beef/lamb at least four nights a week, keep chicken and pork down to 3 at most. That along with a butter / coconut oil focus for oils should keep you in safe territory.

  34. Hair loss is commonly the result of hypothyroidism. I’ve been losing my hair for 50+ years. I’ve had my iodine levels checked many times and they are “normal” whatever that means. I’ve started adding iodine per your instructions in the form of kelp working my way up to a full Iodoral tablet in the ensuing months. Should that do the trick?

  35. erp, what are your TSH levels?

    Hypothyroidism is somewhat complicated, it can be caused by iodine deficiency but by other things too. Eliminating wheat from the diet is the essential first step, supplementing iodine and selenium is the second step, we will have to see if those are sufficient.

  36. Thanks, Peter.

    It would be great if with your help, at last, I could find out what causes my problems.
    All three problems mentioned have been present on and off since my late 20s so they’re not due to the LC weight loss diet (the last 2 years)
    I had bouts of serious acne about 8 years ago too when I was of normal weight, my gum disease was present in my deep pockets 10 years ago, and my hair got thinner progressively but fell a lot a year ago, which could be actually due to the low T3 (measured last year, at my request, outside the range) Constipation needing Mg or lactulose could point to low T3 too as high LDL. The endo does not want to prescribe hormone replacement so I’m left experimenting with diet and supps (Se, Iodine, Zn, Cu, Mg, B vits, vit C, D, fish oil) It seems that it’s not PCOS (scan normal, bloods not conclusive)
    Any second opinion would be appreciated.

    • Hi Simona,

      If your doctor doesn’t want to treat a rather obvious hypothyroidism then perhaps you should find a new doctor.

      Natural healing methods are best: grain, legume, and vegetable oil elimination and selenium, iodine, magnesium, D, and C supplementation are the main keys for the thyroid. It sounds like you’re doing most or all of these. If those haven’t worked then it’s good to provide some thyroid hormone in the meantime while you’re figuring it out. I would include some T3, either the synthetic or natural thyroid extracts. You might want to click on “Hypothyroidism” in the categories and read those posts, for background.

      I believe that most mysterious conditions are due to infections, and since you seem to have chronic infections (gum disease, acne probably due to Propionibacterium, possible vascular infection causing high LDL) it’s possible you have a thyroid infection that is inducing hypothyroidism. I think it’s best to implement the diet and nutritional steps of our book, and then consider possible antibiotic therapies. You definitely want to optimize diet and nutrition first, or antibiotics can easily backfire and worsen the condition.

      But I think normalizing thyroid hormone levels would bring you some immediate relief. Fixing chronic diseases takes time and you don’t want to suffer from low T3 in the meantime.

  37. Oops, sorry, I meant Paul.

  38. Thank you for taking the time to respond. Considering there is infection and/or inflammation present how much C is necessary? You mention 2 g? Is Coq10 necessary too?

  39. Hi simona,

    Not too much C is necessary, 500 mg should do, you just want to avoid a deficiency of carnitine.

    Whether CoQ10 would help is something I would have to investigate. This paper might be a starting point: There’s clearly a connection between CoQ10 and thyroid status, see, but I would expect the causality to run the other way, from thyroid hormone to CoQ10. I think CoQ10 supplementation can’t hurt and has a slim chance of helping the thyroid, so feel free to try it.

  40. I thought it was a good idea to supplement coq10 for gum disease and for high LDL due to its antioxidant function. I have been taking 100 mg for a while but my gums haven’t improved. I read that topical application might help. I might try to put it on dental floss and floss with it.
    I’m taking 1 g slow acting vit C with bioflavonoids, hope it’s absorbed. Probably you have heard of dr. Monastyrsky’s method of dealing with constipation by using buffered vit C early in the morning on an empty stomach. I tried something similar to his Hydro C (similar quantity of vit C) and it didn’t work for me which means maybe I need to increase the dose.
    My acne lesions also seem to heal poorly. I have been taking glucosamine too so I don’t really know what else I could do.
    Maybe it is an immune system problem?

  41. Hi Simona,

    You can’t count vegetables as giving carb calories, so you’ve really been on a zero-carb diet.

    One of the main defects of zero-carb diets is that it generates C/glutathione deficiencies, and glutathione deficiency is along with hypothyroidism one of the leading causes of constipation.

    I would start eating 400 calories/day starches and supplement extra C (now that I’ve noticed you’ve been zero-carb, take a lot more than 500 mg; go to bowel tolerance once, then 2 g/day), N-acetylcysteine, glutathione directly, selenium.

    Why don’t you do those things, follow all of our diet and supplement recommendations, and keep working on getting TSH down to 1. Many of your problems will probably clear, and then it will be easier to evaluate what’s left.

  42. I didn’t think that I was on zero-carb. It seems that I need more than others. I don’t understand why vegetables don’t count as a source of carbohydrate.
    Why does glucose restriction cause glutathione deficiency in some people? (synthesis dependent on cysteine intake, methionine in the liver, homocysteine level – B vits, methylation? nf kappa B? certain insulin and glucose level,

    I’ll be a good girl and increase my starches. I’ve never had that many potatoes or rice in my life. Well, I could change to low carb, which was easy, just avoid all starches/sugars and add cream, now I have to change to more carbs which means being creative and counting for a while. (carrots, beetroots, parsnips, turnips, squash count I hope)

    • Hi Simona,

      The more calorie-rich vegetables like carrots will provide some carb calories, but in general vegetables are not easy for humans to digest. Gut bacteria get the first shot at vegetable carbs, and there aren’t many carb calories to begin with. Moreover the gut and immune cells both consume glucose and digestion of vegetables causes a loss of glucose from both sources – directly and indirectly by making the immune system deal with an enlarged bacterial population. By the time you add in everything, it’s not clear whether there’s a net gain or loss of glucose from eating vegetables.

      Glucose restriction prevents recycling of vitamin C and glutathione is lost in C conservation. Also, C deficiency prevents glutathione recycling. So, on very low carb diets it’s highly desirable to supplement with vitamin C at least.

      The vegetables you mention — carrots, beets, parsnips, turnips, and squash — are all good foods but the last three are not very rich sources of glucose, and the other two have fructose. I would definitely recommend adding in a bit of starches. Check out and see if you can eat at least 200 calories/day glucose+starch, not counting any food with less than 50 glucose calories per pound.

  43. Hi Paul,

    *** “A fecal transplant would be needed to replenish species, which you might consider if the antibiotics go on for a long time.”

    Do you have any recommendations re. how to pursue this, Paul, above and beyond the other mentions you’ve made of fecal transplant in various posts?

    At the very least I’m wondering…

    1. How one would go about choosing a donor (i.e. what weight to place on different criteria such as quality of diet, lack of disease, apparent healthfulness, longevity, family history, etc.)?

    2. Is there a risk of importing pathogens, parasites, new diseases, etc., along with beneficial bacteria – and if so, how could one minimize the risk of doing so?

    I know it’s a bit of a taboo subject, and very much appreciate your willingness to address it.

  44. Hi Sam,

    Well, I would look for a healthy, slender donor with no evidence of bowel infection or leaky gut (autoimmune disease, acne, rosacea, allergies).

    Younger people tend to have more effective immune systems and, especially if they have never had antibiotics, are more likely to have a commensal population. Also, people who eat a good diet will have a healthier flora.

    Yes, pathogens would come in along with probiotic species. But (a) the recipient has probably already been infected with the same pathogens many times before, and (b) the pathogenic species would probably already be present in the recipient’s gut. Remember, pathogens are everywhere. If the species isn’t causing disease in the donor, it’s not likely to cause disease in the recipient, except perhaps for a few-days mild infection kind of symptom.

    The main point is that commensal species tend to get killed by antibiotics, but pathogens don’t because they can hide in biofilms. So antibiotics will give you a pathogen-dominated gut. The stool of a healthy person is commensal-dominated. So fecal transplants are probably making a big improvement in average quality of the gut flora.

  45. Thanks, Paul, that’s good to know.

  46. Hi Paul,

    what you think about this publication?

    Kay Dee italian reader!!

  47. Hi Kay Dee,

    Well, the only surprising part was the orange juice. Fat carries lipopolysaccharide (a fat soluble toxin) from the gut into the body, which is what they found. The level of LPS influx is regulated so if you eat a higher-fat diet the gut becomes less permeable to LPS; I see this as a positive for high-fat diets, not a negative, but if you have a leaky gut then eating fat can generates an inflammatory immune response.

    Glucose doesn’t carry in LPS but elevated blood glucose does affect white blood cells. Orange juice has only half as much glucose (the other half is fructose which goes to the liver) and therefore doesn’t raise blood glucose as much. Perhaps that accounts for the much lower influence of OJ on white blood cells.

    It’s interesting data but I disagree with some of their analysis and find other parts highly speculative.

  48. > You might try cutting fiber for a while. Drop the
    > veggies, stick to white rice over potatoes for a
    > few weeks. Your bacterial population will
    > decrease. Then try the high fat meal and see if
    > your symptoms are gone.

    Hi Paul,

    I was going to try this, because I also have an issue with eating saturated fat (different from Aaron’s though).

    But won’t the fibre from the plant food simply be replaced by resistant starch from the rice? My understanding is that intestinal bacteria will happily ferment resistant starch in place of other plant fibres.

    Calculating from my own intake, if I replace calories from fruit, vegetables and nuts with white rice, my fibre/resistant starch intake will only drop from ~50g/day to ~30g/day.

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