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Book Review: The Perfect Health Diet

After I dissed saturated fat on Facebook a friend told me to read “The Perfect Health Diet”, which usually doesn’t work. But he also offered me a free copy, which does. If you can’t get a free copy, you can get a lot of the material from their website.

Let’s get the obvious out of the way first. The title, dust jacket, and introduction are all doing their best to make it sound like a sketchy diet fad book. Even its proponents admit it does a very poor job at not sounding like a sketchy diet fad book. I don’t know how much importance to give this. Maybe any diet advice, including very scientifically based and sober advice, inevitably ends up looking like a sketchy fad book because that is the most effective way to market it? Let’s just raise the red flag count to “one” and move on.

The best word for my opinions on the content would be “mixed”.

Let’s start with the good. It clearly tries to be science-based. It mostly succeeds. It is evolutionarily informed without being silly about it. It ties a lot of research together into a consistent and conclusive whole.

The overall diet it recommends is…pretty good, actually. Sort of similar to the paleo diet, with its emphasis on unprocessed whole meats and vegetables, and an acceptance bordering on fetish for saturated fat. But it adds the concept of a “safe starch” – where the classic paleo diet has a zero tolerance policy toward carbohydrates, the Perfect Health Diet allows certain carbs like rice, potatoes, and lots of weird things like “taro” and “sago”.

I really like this change. Hunter gatherers do eat certain roots and tubers, so it’s not like an evolutionary perspective has to exclude them entirely. And the Japanese remain some of the healthiest people in the world while eating rice by the bucketload, so anyone who tells you that rice is bad for you has got something like a hundred million contrary data points to overcome. Pre-contact Polynesians were also exceptionally healthy, so all the weird Polynesian starches they recommend have my seal of approval as well.

This makes their diet much easier than normal paleo diets. With a moderate amount of work, you can find a lot of the breadstuffs you like made with rice or potato or something rather than wheat – my local Asian food store has rice noodles that can almost pass for spaghetti to my unsophisticated palate. And since I have been trained not to feel full without some carbs in me, having a small plate of rice with a meal really helps.

I am slightly skeptical about admitting potatoes to the same pantheon as rice and Weird Polynesian Starches. This comes from my four years studying medicine in Ireland. The traditional Irish diet is beef, lamb, butter, cabbage, and potato, which is about as Perfect Health Diet compliant as it’s possible to get (yeah, okay, they do eat bread and drink beer, but other than that). The Irish can be very insistent on sticking to just these couple of things. I remember working at a rural GP office and staying at the home of an elderly Irish couple. I made a trip into town and brought back some spaghetti to make for dinner, and my hosts were impressed that I was making them “exotic foreign foods”. By which they meant spaghetti. This was 2010.

Anyway, despite this rigid diet elderly Irish people seemed pretty unhealthy and cardiovascular-disease-ridden, maybe not much better than the US. If we’re sticking Polynesians and Japanese on one side, and Americans on the other, the Irish are over with us. I don’t know if the Perfect Health people want to blame all of that on their bread and alcohol and whatever ungodly oils they fry stuff in, but I am going to view potatoes with suspicion until this gets cleared up.

The other thing about the book I really liked was their discussion of “toxins”. Normally whenever any diet book discusses “toxins” I throw it aside with great force, because they mean “mysterious evil spirits in foods I don’t like which can be banished only with juice cleanses.” Perfect Health Diet, despite using the same language, singles out very specific chemicals and cites all the reasons which each chemical can be expected to be harmful.

The part that stuck with me most here was their section on omega-6 fats, which might be literally the Devil. I find their speculation on omega-6s and obesity intriguing, not to mention the connection to crime I have already blogged about. Stephan Guyenet seems to take this seriously as well, which is always a good sign. And it makes evolutionary-historical sense that this random stuff we’ve been adding to foods in massive quantities over the past couple of decades and not before is screwing us up.

Also wheat. So, so much wheat. I haven’t had time to investigate this much so far, but a lot of smart people seem very worried about wheat and corn and all those other grains, and if one tenth of the darts they throw at them stick, we should probably start looking for a new staple food for Western civilization.

So much for the good. Let’s move on to the bad.

This book has a very consistent pattern of making a strong claim, citing one study that supports their claim, and failing to mention that there have been many more much larger studies since then that have come to the opposite conclusion.

For example, they mentioned every single study to say breathlessly excited things about Vitamin D for the past fifty years, but failed to mention that all of them have since been disconfirmed by larger and more careful trials.

And it’s not just Vitamin D. Vitamin K prevents prostate cancer! Vitamin K prevents liver cancer! Vitamin K reduces all kinds of cancer by 75%! Vitamin K heals cancer in people who already have the disease! A recommendation: take lots of Vitamin K!

But look at how the American Cancer Society describes these same trials:

A large European epidemiologic study published in 2008 found higher risk of prostate cancer in men with low intake of some forms of vitamin K. But people who take in plenty of vitamin K usually get it from fruits and vegetables. This means that people who get lots of vitamin K from foods are more likely to take in many other vitamins and phytochemicals that can affect cancer risk. In some cases, vitamin K may be given credit for benefits that are actually due to other compounds that appear in the same foods. So studies like this, which only observe large groups of people, may not be very useful for looking at the effects of vitamin K intake.

A small clinical trial from Japan suggested that vitamin K lowers the risk of developing liver cancer among women with cirrhosis due to hepatitis C. A later study also seemed to show some effect, but it was not statistically significant. Further study is needed.

There have been some studies examining whether menadione (vitamin K3) can help overcome cancer cells’ resistance to certain types of chemotherapy drugs. Results in lab animals and cell cultures are mixed, but there is no evidence available of significant effects in humans yet.

A small Phase I clinical trial in California tested different doses of intravenous vitamin K3 in people with advanced cancer. The patients did not improve. In that study, several patients also had allergic reactions, especially at higher doses.

Look. I know alternative medicine is hard to do. It’s also useful. Sometimes they come up with genuinely interesting stuff the mainstream has missed. So I’m not demanding that you not speculate about Vitamin K just because the mainstream medical community has interpreted the results as unimpressive. Go ahead and try to find reasons why the earlier successful trials were more believable than the later more pessimistic trials. But at least mention that everyone else disagrees with you about this. Don’t present it as some well-established thing which the mainstream community is just completely ignoring.

We repeat this exact same frickin’ pattern with just about every vitamin and mineral ever discovered. Selenium prevents gastric cancer! Selenium reduces tumor incidence! A randomized controlled trial of selenium in China decreased liver cancer! A trial of selenium in America decreased skin cancer! Selenium improves immune function! Selenium decreases all-cause mortality by a quarter! Selenium cuts cardiovascular mortality in half! Selenium cures all diseases! Selenium will make you rich and famous! Women will want to date you! Men will want to be you! You will live in a beautiful house on the beach, with a huge yacht made entirely of selenium! You will sail it over seas of liquid selenium, to selenium islands where selenium-based life-forms play haunting music beautiful beyond anything you have ever imagined upon their selenium flutes. If you take enough selenium you will never die, yet if by chance you should, you will go to Selenium Heaven, which is to regular Heaven what a supernova is to a firefly.

Meanwhile, look at any respectable medical source like Cochrane Review, and the actual list of effects that they find for selenium is exactly zero. The process is the same as always. Some preliminary exciting studies come out. So we do much bigger, more rigorous studies and the effects go away. I did a really thorough evaluation of the selenium literature for my Quantified Health Prize entry and although I was totally happy to disagree with expert advice in several areas, in the case of selenium I found that the experts were exactly right and it is useless. Perfect Health Diet doesn’t even mention the expert consensus or rigorous studies here.

This leads to this weird pattern where Perfect Health Diet manages to explain about 1500% of human mortality. That is, if you add up all of their claims (“Vitamin Q decreases mortality by 50%!” “Vitamin R decreases mortality by 75%!”) then although I haven’t exactly done the calculations my guess is they would add up to around 1500%. This isn’t quite mathematically impossible – if there are fifteen vitamins, any single one of them prevents cancer completely, and you can just choose which one you want – then added together they would decrease cancer mortality by 1500%. But even though it’s not mathematically impossible, it doesn’t seem right to me and it seems much more likely that they use hugely inflated claims than that fifteen different interventions all cut mortality even more than any of the things we know cut mortality like exercise or quitting smoking.

I’ll skip over the T3/T4 thyroid thing and a few others that will be more of the same, and just spare a second to complain about folic acid: they say supplementing pregnancies with folic acid causes autism. This is not only not proven, but there’s much stronger evidence for the opposite: multiple good studies show folic acid supplemention decreases autism risk by as much as 40%. Perfect Health Diet’s only source for the opposite claim was a correlational study in, of all places, the Journal of Medical Hypotheses, which specifically exists to signal-boost claims that don’t really have any support but need further investigation.

Now, to be fair to PHD, they did briefly mention this counterexample. But their scare study was in bold and exaggerated, and the existence of a counterexample was in parentheses and had the word “slightly” appended to the front even though it was not slight at all.

So. Alternative medicine people? Please listen very closely. STOP SAYING THAT VITAL CHILDRENS’ HEALTH INTERVENTIONS CAUSE AUTISM. THIS. NEVER. HELPS.

Overall I thought their entire section on vitamin and mineral supplementation was a disaster area. This is a little worrying because I know more about vitamins and minerals than I do about macronutrients and diet in general, and the Gell-Mann Amnesia Effect argues that if the parts you know something about are bad, you should assume the parts you don’t know enough to criticize are as well.

I will, however, give praise where praise is due. PHD gets that multivitamins aren’t a great idea and does not recommend them. It gets that calcium is not a great idea and doesn’t recommend it either. And they have praise for iodine and lithium, which are the two minerals I went out on a limb to recommend in my QHP entry and which I really do think deserve more attention than they’re getting.

In conclusion, PHD is not a terrible book and you could do much worse as far as diet books go. It is written by smart people who are familiar with at least some of the literature. It is a good idea-generation source to learn about things you might not have otherwise known (did you know there is some evidence a chronic bacterial infection can be one cause of Alzheimers Disease?) and the diet it recommends will probably not kill you and in fact probably be good for you. If their stuff about wheat and omega-6 and the like pans out, and I would not be surprised if it does, it might be really good for you. I don’t have any complaints there.

(actually, I tried the diet they recommended for about two weeks, just to see what would happen, and I lost seven pounds without really trying. This is a sufficiently large number of pounds that I find this result implausible and am hesitant to pronounce a “This is what happens when you follow Perfect Health Diet”. But still, nice.)

But I also cannot wholeheartedly recommend it, especially for epistemically-minded people who want something correct as opposed to something full of nice diet advice. It has a lot of shoddy research and presents extremely controversial positions as if they are settled science. There are very few mistakes that will kill anyone (they even couched their folic acid advice with an incongruous yet welcome “but you should still take a little folic acid during pregnancy”) but a lot of mistakes that will leave you very confused or have you taking very silly amounts of vitamins.

This book might be suitable for someone who wants to try a paleo-inspired diet for purely practical reasons, but who needs some encouragement and inspiration through a discussion of the science behind it. It might also be good for someone who already knows a lot about health from a mainstream point of view, is sufficiently skeptical to catch the mistakes, and wants to see what sorts of stuff the paleo diet and alternative-medicine-which-is-smarter-and-more-sciency-than-homeopathy people are about so they can grab the useful insights and discard the rest.

I was originally sent this book because I dissed saturated fat, so I should tie up my review there – especially since it makes a good metaphor for the book in general. Perfect Health Diet gives a lot of good evolutionary reasons why saturated fat might be good for you, and reflects the growing consensus that yeah, we kind of went overboard turning it into demon-food and should take a step back from there – something most people don’t realize and that this book could be very helpful in teaching.

But then it goes on to say that the old story that saturated fats led to heart disease has been debunked, citing as the only discussion for this claim a link to a systematic review that did in fact find saturated fats not to correlate with heart disease. What the book doesn’t mention is that this study was funded by the National Dairy Council, or that nine out of eleven other systematic reviews that have investigated the issue did find a saturated fat/heart disease link, or that Cochrane Review, which is the gold standard for systematic reviews of medical evidence, concluded that on balance there is good evidence for a saturated fat-heart disease link. All they do is cite the increasingly-lonely one that found the conclusions they wanted, declare that to be the state of the evidence, and move on.

So that is PHD in a nutshell. Interesting points, broadly reasonable dietary advice, and total denial of the existence of any evidence that doesn’t support their claims.

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93 Responses to Book Review: The Perfect Health Diet

  1. Mqrius says:

    THANK YOU! <3

    I had been seeing PHD mentioned all over, and avoided it at first. After I got some repeated exposure, I did notice that its claims didn't seem to be as bad as my priors led me to expect. So I bought it, and it's sitting on my shelf.

    …But I trust your analysis lots more than PHD. Good thing you made this review before I got a chance to read it. Seeing as books tend to sway me too much, I might have actually been convinced by some of its broken points 😡

    So yeah, now I could read it with the appropriate precautions. But I don't really need to anymore.

    Cheers 🙂

    • Scott Alexander says:

      I would still suggest you read it. You sound like you have the right mindset to get something out of it. And I’d be interested in confirmation or disconfirmation of my impression.

      • Mqrius says:

        Alright, I will. At the very least I should be able to identify the parts that are clearly established science (nutrient interactions, not health benefits), which should serve to correct flaws in my knowledge base.

        It’s high value to me, since I’m doing 100% DIY Soylent. I’m at 5 months now; just got the latest blood results.
        Speaking of which, may I pick your mind for a second?

        So, the latest test shows I have low iron (45 μg/dL, normal range 65-166). This in itself is not expected, I’ve always had relatively low (around 60). It has dropped and my calcium has risen, which tells me I should put less calcium in my Soylent so metal uptake isn’t prevented as much. (Zinc and copper are on the low end of normal too, so it all works out)

        The funny thing is though, my Hemoglobin is perfectly fine. (14.3 g/dL, normal range 12.5-17.1). Which is funny, because in the end, it’s the hemoglobin that’s going to matter to me. Seeing as iron has a strong effect in inducing oxidation, should I even want to increase iron if my Hb is fine?

        (They didn’t check red blood cell count, so I can’t check MCV/MCH/MCHC unfortunately. I’ve asked them if they can still test it on the same blood sample, but I haven’t had a response yet.)

        Currently I’m planning to reduce calcium and get iron back in the 60s range, but that’s still low compared to normal values. Is there any benefit to increasing it further, if my Hb is fine anyway?

        [I am aware that you are not licensed to give me medical advice and will not construe it as such.]

  2. Sebastian says:

    and lots of things no real person eats like “taro” and “sago”.
    I think they’re quite staple in some parts of the world – I’m sure you didn’t mean to imply that people in Asia and Polynesia aren’t real, but it’s rather a careless phrasing.

    • Brian says:

      Plenty of taro lying around when I was staying in Hawaii, yeah. And that’s pretty Westernized as Polynesian regions go.

    • Oliver Mayor says:

      Thanks, Sebastian. Taro and sago are not weird! How dare you, Scott Alexander.

      –Highly biased person of Austronesian descent

    • vare2 says:

      Haha yes ! From another _real_ person who eats and appreciates both. Although to be fair, they are more often eaten as desserts rather as a main source of energy like other carbs.

      Scott if you’re ever in San Mateo, I’ll be happy to take you out to try out both

  3. Would it be possible to add “follow comments without having commented”?

  4. ephion says:

    How do you feel on the diet? You mention losing 7lbs, but how do you feel physically, mentally, etc.?

    • Randy M says:

      I’m kinda confused by the “lost 7 pounds seems implausible so disregard it” comment. Presumably 1-2 or even 1-3 or 4 pounds would be too small to attribute to the diet. Is 5 the magic number that makes sense but matters?

      • misha says:

        there’s a lot of stuff that can cause one to lose varying amounts of pounds over a few days such that you shouldn’t try to extrapolate short term losses/gains to the effects of a diet. EG, I can gain 9 pounds over like 4 days when I go back to eating carbs, but that doesn’t mean I’ll sustain that rate indefinitely.

    • Thank you for raising the question. “Lost weight” isn’t a good surrogate for “is healthier”.

    • Scott Alexander says:

      Strong positive placebo effect at first, afterwards got swamped by moving to a different work schedule in which I had different sleep hours and couldn’t disentangle that from the diet.

  5. James says:

    Thanks! I roughly follow this diet, and am glad to have your analysis as a source of doubts and potential tweaks. On the potato question, you said this:

    The traditional Irish diet is beef, lamb, butter, cabbage, and potato, which is about as Perfect Health Diet compliant as it’s possible to get (yeah, okay, they do eat bread and drink beer, but other than that).

    And this:

    [D]espite this rigid diet elderly Irish people seemed pretty unhealthy and cardiovascular-disease-ridden, maybe not much better than the US.

    To be fair, the Perfect Health Diet advocates variety, particularly in plant foods:

    The Paleo principle – it’s healthiest to eat like a caveman – is a good guide to low-toxicity eating. Paleolithic peoples gathered a wide variety of plants – hundreds of species – and did not eat the Neolithic agricultural crops. Agriculture needs plants that produce an abundance of calorie-rich seeds, but these are precisely the plants that load their seeds with high levels of toxins to discourage herbivores.

    They also advocate eating lots of non-starchy plants by volume, though this ends up being a minor source of calories.

    A further source of evidence (which I don’t think you mentioned) is the effect on those taking up the diet. They report impressive-sounding results for readers, particularly improvements in long-standing and debilitating conditions. Where conditions are long-standing, such improvements are less likely to result from regression to the mean (though we might assume a reporting-positive-results bias).

    • Brian says:

      Paleolithic peoples gathered a wide variety of plants – hundreds of species – and did not eat the Neolithic agricultural crops.

      This looks technically correct but misleading to me. My understanding is that forager cultures, or at least the contemporary ones outside the Arctic, know about a lot of food plants but rely on a much smaller set of them for day-to-day eating.

      I can’t find the cite now, but I distinctly remember an article talking about how earlier researchers had been looking at festival fare and been greatly impressed by its variety, but that modern ethnographers, staying for longer periods, consistently found that their diets got a lot more boring once their subjects got used to their presence.

  6. Randy M says:

    Has anyone else read “Death by Food Pyramid?” I found the author to be balanced and measured in her recommendations, though I’d like a critical opinion as well if anyone else has seen it. The book is new, but I bought it after being impressed with her blog, rawfoodsos.com.

    Regarding saturated fat and heart attacks, I’ve been seeing some news lately even outside of alternate diet sites that dietary cholesterol has been de-linked from blood-serum cholesterol, for example my insurance web site promoting eggs, etc. Is the establishment turning around on this point?

    • Alexander Stanislaw says:

      Disclaimer: I’m not an expert

      It is still controversial. Dietary cholesterol does increase blood cholesterol levels. However, no credible nutritionist uses total cholesterol as a measure of anything. The ratio of HDLs to total is more important. This analysis claims that dietary cholesterol increases the ratio of total to HDLs (which is supposedly bad).

      However, this study found no effect of eggs on heart disease or stroke except among diabetics. And this one claims that there is no link between dietary cholesterol and CHD mortality. Of course eggs are not composed of just cholesterol.

      The first author I cited disagrees, based on the risk factor of HDL to total cholesterol he extrapolates a 2% increase in the lifetime CHD risk if you were to eat the cholesterol from 1 egg per day. Actual data would be preferable though.

      This cohort study also found no effect of eggs on CHD in Japanese adults. This one did find a positive effect of dietary cholesterol on CHD but it also found a larger positive effect of protein and fat on CHD. I’m not sure what to make of that.

      • US says:

        I’m not an expert, but I’ll try to limit my comment to talking about what the experts think…

        “dietary cholesterol has been de-linked from blood-serum cholesterol.”

        I haven’t followed those news, but this doesn’t sound right. The textbook I read on the topic a short while ago is not that old and came to different conclusions.

        Alexander Stanislaw is, according to the textbook (I’ll leave a link at the bottom), correct to observe that: “Dietary cholesterol does increase blood cholesterol levels.” His remarks on the usefulness of the HDL/LDL (/’non-HDL-‘)-ratio (very-low-density-lipoproteins also matter) are correct as well. There’s more to this discussion than just HDL and LDL, though, as implied in the parenthesis. Hypertriglyceridemia is an independent risk factor for coronary heart disease as well.

        Below I’ve added a little more about this stuff from the aforementioned textbook which may be of interest:

        “Relatively consistent evidence indicates that increasing the carbohydrate content of the diet at the expense of fat results in dyslipidemia [7–9]. The majority of the evidence suggests that carbohydrate-induced hypertriglyceridemia results from an increased rate of hepatic fatty acid synthesis [10,11] and subsequent production of hepatic triglyceride-rich particles, verylow-density lipoprotein (VLDL) [12–14]. […] Within the context of a stable bodyweight, replacement of dietary fat with carbohydrate results in higher triglyceride and VLDL cholesterol concentrations, lower HDL cholesterol concentrations and a higher (less favorable) total cholesterol to HDL cholesterol ratio [16–21]. These effects are blunted when an individual is in negative energy balance, the carbohydrate source is rich in fiber, and perhaps when subjects are engaging in regular physical activity [7,19,20]. Sedentary individuals characterized by visceral adiposity are at particularly high risk for carbohydrate-induced hypertrygliceridemia [9].”

        “Studies performed in the mid 1960s demonstrated that changes in dietary fatty acid profiles altered plasma total cholesterol concentrations in most individuals [27,28]. Many studies have since confirmed these early observations using a variety of different experimental designs [29]. When carbohydrate is displaced by saturated fatty acids, LDL cholesterol concentrations increase, whereas when carbohydrate is displaced by unsaturated fatty acids LDL cholesterol concentrations decrease, with the effect of polyunsaturated fatty acids greater than monounsaturated fatty acids […] When carbohydrate is displaced by saturated, monounsaturated or polyunsaturated fatty acids, HDL cholesterol concentrations are increased, with saturated fatty acids having the greatest effect and polyunsaturated fatty acids having the least effect. With respect to dietary fat on LDL cholesterol/HDL cholesterol ratios, there is little effect when carbohydrate is displaced by saturated fatty acids, whereas monounsaturated and polyunsaturated fatty acids decrease (more favorable) the ratio to a similar magnitude. Relative to carbohydrate, all types of dietary fat decrease triglyceride concentrations.”

        The quotes are from the Wiley-Blackwell publication Metabolic Risk for Cardiovascular Disease. I blogged the book on my blog here, where you can read a bit more about it.

    • Douglas Knight says:

      All sources of dietary cholesterol have lots of saturated fat, which definitely does raise blood cholesterol. But my impression is that the direct effect of dietary cholesterol is sympathetic magic.

      • Douglas Knight says:

        Actually, shellfish is a big source of dietary cholesterol with little fat.

        I take back the claim that it is purely magical thinking. I found lots of false citations, but there are papers that try to disentangle saturated fat from cholesterol. Here is a 1997 paper that claims that the effect of an egg on serum cholesterol is 3 times as much from the dietary cholesterol as from the saturated fat.

        But you asked about more recent studies. I don’t know. I worry that the reports you hear are people like me, who conclude from false qualitative citations that no real results exist.

  7. Flyreme says:

    From my personal observations, “I tried the diet and lost x pounds” is pretty poor evidence of a diet working unless you are controlling for the number of calories you eat. I suspect it’s because most people who go on diets just eat less food because they’re now paying close attention to what they’re eating, and because they’re not used to having to eat within those specific requirements so they have less of that food available, haven’t worked out what they really like that they can make within them, etc…

    (Unless, of course, the diet is supposed to work just by making you eat fewer calories.)

    • Anonymous says:

      No diet would work if you controlled for calories eaten–all diets work by causing you to eat fewer calories, because that’s the only way to lose weight long term. (of course, changing your diet can increase or decrease water retention, which is why Scott could lose 7 pounds in 2 weeks. He couldn’t have lost 7 pounds of fat in 2 weeks, it was mostly or possibly entirely water weight)

      Part of the reason diets work is that you’re paying closer attention to what you’re eating, but if you pay attention to what you’re eating and are hungry all the time, the diet won’t work long-term. The best way for a diet to work long term is replacing less satiating calories with more satiating ones. Liquid carbs, for example (soda, fruit juice, etc) have lots of calories, but aren’t satiating at all (don’t fill you up), while protein and fat are very satiating. So if you stop drinking soda and just drink water instead, you’d feel just as full with fewer calories. Or if you replace less filling foods like chips and candy with bacon and vegetables.

      • Flyreme says:

        “[eating fewer calories] is the only way to lose weight long term” is something that a lot of diets explicitly claim to be false. Consider keto, which claims that calories are a much worse thing to focus on than carbohydrates. In these cases, controlling for calories seems very important to testing their claims.

        I’m curious why you assert that calorie intake is the only long-term thing our weight is based on. I’ve never seen good evidence for or against this claim. Got sources?

        • Alexander Stanislaw says:

          Erm, the law of conservation of energy? You’ll only lose weight if calories out is greater than calories in (obviously not counting water weight). Don’t read too much in to this statement – I’m not arguing against diets or arguing in favor of calorie counting – I’m stating the physical mechanism of weight loss. If carbohydrate restriction causes weight loss, then it causes weight loss because it causes you to take in fewer calories than you burn.

        • Randy M says:

          That is probably true, but isn’t logically the only possible way.

          It could be that certain macronutrients invoke, sometimes, hormonal feedback to make metabolism less efficient (so more energy is converted to heat per ATP used, etc.) or digestion less efficient or whathaveyou.

          The thing to keep in mind when discussing the plausibility of diet theories is that we are giant bags of terribly complex and diverse chemical reactions–not quite bomb calorimeters.

        • Alexander Stanislaw says:

          It could be that certain macronutrients invoke, sometimes, hormonal feedback to make metabolism less efficient (so more energy is converted to heat per ATP used, etc.) or digestion less efficient or whathaveyou

          Which still obeys the calories in/out model. Less efficient metabolism => more calories out. More inefficient digestion => fewer calories in.

          we are giant bags of terribly complex and diverse chemical reactions

          Absolutely.

        • Randy M says:

          Okay, yes, but it does disagree with the “the only difference in diets is how much you eat” in Flyreme & anonymous’ conversation. Usually when people say calories in they–okay, maybe just me?–mean into the mouth, without considering there can be intake differences in the gut or cells, etc.

        • Anonymous says:

          http://en.wikipedia.org/wiki/Energy_balance_%28biology%29
          The energy balance equation (calories in-calories out) is generally accepted as true because of thermodynamics and such. It is possible that there are exceptions, like what keto claims to do, but there are none that I know of that have noticable effects on weight gain/loss.

          Technically, the energy balance equation isn’t always as simple as the law of conservation of energy. You can digest different calories at different rates of efficiency, there’s the thermal effect of food (you burn calories to digest food), and other things. This article discusses in in depth, if you’re interested. http://www.bodyrecomposition.com/fat-loss/the-energy-balance-equation.html

          But calories in-calories out is close enough to the truth for all practical purposes.

          Some people claim to try and claim they are an exception to calories in/calories out, because of genetics/thyroid/whatever, but they’re wrong. Some studies have found this, but only ones where caloric intake is self-reported, rather than controlled by experimenters. In this study, obese people dieting overestimated their caloric intake by 47%, and underestimated their physical activity by 51%, which is really why they failed to lose weight.
          http://www.ncbi.nlm.nih.gov/pubmed/1454084

          Keto people claim that ketosis offers a metabolic advantage in addition to the calories cut, but I’ve never seen any evidence for this.
          http://ajcn.nutrition.org/content/83/5/1055.full
          The actual reason some people lose weight rapidly with keto diets is that ketogenisis can have appetite reducing effects.

          Also, you can of course lose weight by exercising more. Mispoke in my first post, meant that the only way *diets* cause you to lose weight is through caloric restriction.

        • Anonymous says:

          The comment filter seems to have blocked my previous post, I assume because of all the links. So here’s the post without links, just google the stuff in brackets and you should be able to find it.

          [wiki page on energy balance (biology)]
          The energy balance equation (calories in-calories out) is generally accepted as true because of thermodynamics and such. It is possible that there are exceptions, like what keto claims to do, but there are none that I know of that have noticable effects on weight gain/loss.

          Technically, the energy balance equation isn’t always as simple as the law of conservation of energy. You can digest different calories at different rates of efficiency, there’s the thermal effect of food (you burn calories to digest food), and other things. This article discusses in in depth, if you’re interested. [bodyrecomposition energy balance equation]

          But calories in-calories out is close enough to the truth for all practical purposes.

          Some people claim to try and claim they are an exception to calories in/calories out, because of genetics/thyroid/whatever, but they’re wrong. Some studies have found this, but only ones where caloric intake is self-reported, rather than controlled by experimenters. In this study, obese people dieting overestimated their caloric intake by 47%, and underestimated their physical activity by 51%, which is really why they failed to lose weight.
          [Discrepancy between self-reported and actual caloric intake and exercise in obese subjects.]

          Keto people claim that ketosis offers a metabolic advantage in addition to the calories cut, but I’ve never seen any evidence for this.
          [Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets]
          The actual reason some people lose weight rapidly with keto diets is that ketogenisis can have appetite reducing effects.

          Also, you can of course lose weight by exercising more. Mispoke in my first post, meant that the only way *diets* cause you to lose weight is through caloric restriction.

        • Misha says:

          Conservation of energy based arguments are the nutritional equivalent of talking about spherical cows. They’re useless and should be left behind. If you think the amount of energy gained from something by burning it is the only important factor in food please go eat some wood. Or if you want an obvious example from diet: tell me how my lactose intolerant digestion gets the same amount of calories from a glass of milk. Oh it turns out nutrient composition can matter? THAT’S NOT EVEN TALKING MACRONUTRIENTS. A variant of sugar can have different caloric impact on different people. It may yet remain true that a caloric deficit is the only way that diet works. But please don’t pretend your thermodynamics argument is proof of it, or of anything.

          And PLEASE don’t use it if you’re then going to talk about different levels of uptake and effects on expenditure. That just proves how useless the original “calories in calories out” phrase is in the first place.

      • Alexander Stanislaw says:

        @Randy

        Good point, I suppose my definition of “calories in” is a bit weird.

        @Misha

        I don’t understand your anger, is it because you are pattern matching us to people that say “you’re just fat because you eat too much”? Because we’re not saying that.

        Wood doesn’t contain any significant calories that are usable by humans, and both Anonymous and I have agreed that the caloric content of food eaten is not the same as “calories in”: I doubt the difference is very large though except in extreme instances such as wood. And certainly neither of us has said that nutrients are all the same.

        The reason were having this conversation is because Flyreme wanted to know if calories in/out is true*. Not useful from a dietary perspective (because it isn’t), but true. And it certainly is.

        *Although I just realized he was questioning the “calories in” model as opposed to the “calories in/out” model.

        • misha says:

          Imagine we were having a conversation about geology or evolution and you said “I think god created the earth”. I then respond with something anti-creationist and angry. Because you are saying something useless to the rest of us and dumb. If you then elaborate with “Oh I meant god created the earth over billions of years using evolution and erosion”, then you’re only being even more useless. That’s why I’m annoyed. The mantra of calories in calories out is used by idiots to say dumb things. Regardless of whether it’s technically true, it’s not functionally useful in conversations about diet or exercise.

      • Desertopa says:

        You can lose 7 pounds of fat in 2 weeks. I’ve done it before, and for that matter, I’ve extended it and lost about 20 pounds of fat in 6 weeks.

        However, this generally takes intensive exercise in addition to diet control, and it’s around the maximum rate of weight loss that’s not considered to be a health risk.

      • James Babcock says:

        > No diet would work if you controlled for calories eaten–all diets work by causing you to eat fewer calories, because that’s the only way to lose weight long term.

        This is completely wrong. Different diets will cause the body to use different amounts of energy, despite having the same number of calories.

        What you wrote here is a stronger claim than the energy balance equation, which is also wrong, but more subtly so. I see from other replies that, when challenged, you silently retreated to that weaker claim. Since you are anonymous, I can’t chastise you properly, but please, we’re trying to make sense of a confusing topic and you are not helping.

  8. Andy says:

    STOP SAYING THAT VITAL CHILDRENS’ HEALTH INTERVENTIONS CAUSE AUTISM. THIS. NEVER. HELPS.

    I laughed far too hard at this.

  9. Alexander Stanislaw says:

    An aside: Do comments with too many links get moderated?

    Thanks for the review, I was really hoping for your opinion on wheat, but ah well. This diet sounds almost exactly like Mark Sisson’s primal diet which I’ve seen mentioned on LessWrong. East Asian cuisines seem to satisfy many of the requirements pretty easily, which is fine by me since those are my favorites.

  10. Sarah says:

    I also recently read the PHD!

    I’d been avoiding learning about nutrition forever because AACK BODY IMAGE. As a result, I did not know things like “ketones are used by the brain as an alternative energy source” or “polyunsaturated fatty acids are used as receptors on cell membranes.” Kudos to Eliezer for reminding me that nutrition is, y’know, SCIENCE, not just a black hole of angst, and worth learning about if you want to be a well-informed human.

    I’d rate the PHD as maybe an 8/10 on the angst-avoiding scale. They really do go out of their way to maintain a calm and reasonable tone, and not call all their readers fatasses. I got through it with only a little hyperventilating.

    Mostly, it seemed that the strongest arguments were for the idea that the “natural” diet comes from a majority of calories from fat, a minority from carbs and protein. They get the same results from a wide variety of types of evidence: hunter-gatherer diets, animal diets, physiology, etc. I’m also convinced that sugar is bad for you and that omega-6 is better than omega-3, because the experimental evidence seems overwhelming.

    Wheat is more confusing. Their case relies heavily on the fact that lots of people have antibodies to wheat. If the immune response is severe, you get celiac disease. I’m less certain that it means something to have a mild wheat allergy. The authors take it as pretty much self-evident, and add so me correlational studies about bad effects of wheat, and it just doesn’t seem like enough, but I may change my mind.

    The contention that a wide variety of chronic diseases are really infections is just…WTF. It’s an extraordinary claim without extraordinary evidence.

    • “omega-6 is better than omega-3”

      Typo or surprising claim?

    • Alexander Stanislaw says:

      The contention that a wide variety of chronic diseases are really infections is just…WTF

      Haha, yeah. Have you heard of the “gay germ” hypothesis? Pretty much what it sounds like. The guy who came up with it also thinks that Cancer and many mental illnesses are caused by pathogens.

      • Douglas Knight says:

        You’re probably talking about Paul Ewald, who wrote a book on the subject or his collaborator Greg Cochran, who has a blog.

      • Scott Alexander says:

        Cancer sometimes is caused by pathogens. See infectious causes of cancer. It would not surprise me if a lot of sporadic cancers were caused by or exacerbated by random pathogens in a long-tail sort of way.

        Mental illnesses can definitely be caused by pathogens in utero – kids of mothers who suffered various viral infections in utero are 5x – 10x more likely to have certain things like bipolar disorder and schizophrenia, and we also have a lot of epidemiological data suggesting a link. OCD can occasionally be caused by autoimmune response to a strep infection, and there has been mild success in correlating some schizophrenia cases with toxoplasma gondii.

        The “gay germ” hypothesis would be a very straightforward application of a large amount of research showing that infectious in utero can cause mental conditions (I’m not calling homosexuality a “mental condition” in some moral sense, only in the “an unexpected and counter-evolutionary change from normal brain function that can profitably be compared to other such changes”). My main objection to it would be that it would be very unusual for these infections to be the only cause of something – more likely homosexuality is similar to a lot of other conditions where genetic, in utero, and environmental factors all combine to produce risk.

        • Alexander Stanislaw says:

          Certainly pathogens can do a lot of things – it is his attempt to explain everything that isn’t yet understood with pathogens that makes me raise an eyebrow. He’s pretty obviously hunting for nails. I haven’t looked at his work in detail, so maybe I should just reserve judgement.

    • Scott Alexander says:

      “The contention that a wide variety of chronic diseases are really infections is just…WTF. It’s an extraordinary claim without extraordinary evidence.”

      I wasn’t too turned off by it. If we consider things like h pylori/ulcers, the hypothesized adenovirus/obesity connection, and all the different things that cause cancer (HPV, EBV, schistosomiasis, hepatitis, etc), it’s a known mechanism that for all we know might be more common than we think.

      If we expand it from “effect of chronic infection” to “effect of dysregulated immune response to infection”, we can add in a lot of autoimmune disorders, PANDAS, probably diabetes, probably MS, et cetera.

      While I doubt more than a small percent of the things we currently think are noninfectious will turn out to be infectious, there’s a lot of room for surprises in that prediction.

  11. @johnwbh says:

    Is your Quantified Health report available online anywhere? The links on [the original lesswrong article](http://lesswrong.com/lw/a60/quantified_health_prize_results_announced/) are broken at time of writing.

  12. Douglas Knight says:

    a paleo-inspired diet for purely practical reasons

    What does that mean? does “practical” mean short-term, weight loss as opposed to long-term health?

    • Scott Alexander says:

      As in “reading this book for advice about what food to eat, not because you want to hear about lots of studies and learn how human metabolism works”

      • Randy M says:

        I think the confusion came up because there is a bit of an impression that the actual practical advice isn’t necessarily true–and therefore useful–due to neglecting disconfirming evidence, though you do say that following it is “broadly reasonable.”

        • Douglas Knight says:

          I think that was what I was thinking. But just now I went and reread the sentence I quoted and I’m confused, both about what I was thinking and still about what Scott means.

          This book might be suitable for someone who wants to try a paleo-inspired diet for purely practical reasons, but who needs some encouragement and inspiration through a discussion of the science behind it.

          It’s for someone who already knows that paleo is correct and wants arguments for it? That sounds like a dangerous bottom-line reasoning approach. Maybe you trust your friends to have correctly identified the right diet, but you irrationally need details as cheerleaders? Or maybe you do need the details to implement the diet?

  13. I continue to be dubious of the saturated fat->CVD hypothesis. Look at the Cochrane review, a huge list of things you would expect to correlate to increased risk show no effect and one particular measurement does. I am also not confident that processed meat is being well controlled for. I am also not confident that increased MUFA does not have an outsized effect that accounts for the difference. Regardless of the back and forth in PUFA vs SFA, the evidence for MUFA being good for us seems pretty strong.

  14. Mike Johnson says:

    Scott- three comments.

    (1) Death by Chocolate (and other New World substances):
    Greg Cochran argues that Old World populations (such as you and I) may not be as well-adapted to New World foods as we assume. Corn, potatoes, chocolate- all of these could be causing problems, because their biochemistry is so novel to us (and plants often try to make their biochemistry toxic to animals so they get eaten less).
    http://westhunt.wordpress.com/2014/02/26/death-by-chocolate/

    (2) Toxic multivitamins:
    Louie Helm argues that multivitamins are a wash– not because they don’t do anything good, but because they also have chromium and manganese, which actively do bad things.
    http://rockstarresearch.com/most-multivitamins-have-these-2-toxic-minerals-in-them/

    (3) Wheat:
    You seem to be receptive to the idea that wheat can be bad for people, much moreso than we generally accept. I agree with this, and endorse what you wrote wholeheartedly! On the other hand, one of the bloggers you follow suggests

    There is no actual evidence that gluten is in any way bad for 99% of the American population. A small fraction of Americans (less than 1%) are allergic to gluten, and must avoid it because they’re allergic. To the rest of us, gluten is harmless.

    http://rationalconspiracy.com/2012/08/15/gluten-a-public-service-announcement/

    I won’t put you on the spot regarding whether you think ze’s wrong, but I would be interested to hear both rationales.

    • Scott Alexander says:

      I admit I haven’t investigated wheat very well. I usually trust JRayhawk, who says it’s horrible, but I also trust Alyssa. I should look into this.

      The New World thing seems very strange. First, it’s explaining non-data – as far as we can tell, chocolate is good for people, especially when you control for stuff like sugar. Second, I’m not sure why some random guy of some particular Old World culture should be more adapted to all of the Old World stuff outside their personal Old World region than to New World stuff.

      • Mike Johnson says:

        Yeah, Cochran’s blog is always subtly tongue-in-cheek so I’m not exactly sure what his precise stance on chocolate is (i.e., did he just pick chocolate because it led to a clever title for the post?). But, this could in theory help explain your data on Ireland (they eat lots of potatoes, a New World crop, and have poor health outcomes).

    • Prussian Prince of Automata says:

      The Death by Chocolate thing read to me like a Reductio ad Absurdum of one of the more obnoxious anti-GMO arguments; if we shouldn’t eat genetically modified food because it’s ‘unnatural’ or ‘not what we evolved to eat’ then you’ve got to throw out maize cocoa potatoes and a bunch of other staples for the same reason.

      At the same time, there may be a hint of truth to it as well; just like Amerindians have high rates of alcoholism corresponding to their low historical exposure, we Europeans aren’t exactly exercising much in the way of restraint with chocolate or any of the other superstimulus foods we only really got access to fairly recently.

  15. nydwracu says:

    Also wheat. So, so much wheat. I haven’t had time to investigate this much so far, but a lot of smart people seem very worried about wheat and corn and all those other grains, and if one tenth of the darts they throw at them stick, we should probably start looking for a new staple food for Western civilization.

    Rice and beans were once the staples of the South, so there’s the easiest alternative. There’s even rice cereal!

    On the subject of Polynesians, they’ve started selling breadfruit around here. But that’s loaded with sugar.

  16. BenSix says:

    What do they have against legumes? I will cheerfully admit to being biased, because I think that using animals for food should be avoided where possible and lentils are a great alternative to them, but I tend to see a lot of evidence that they are parts of healthy diets and only vague grumblings about toxins from people who don’t seem to appreciate that we have acquired the ability to cook food.

    Also, I hope there is a difference between liquid fats and whole foods because I eat more nuts than the entire squirrel population of the North Americas.

    I am going to view potatoes with suspicion until this gets cleared up.

    Does this also entail treating beef, lamb and butter with suspicion?

    • BenSix says:

      (Tribesmen have apparently been eating the high linoleic acid mongongo nuts as a staple for millenia which offers some comfort to my omega 6-addled brain.)

      • Scott Alexander says:

        Clearly the mongongo nut consumption and subsequent brain-addling explains why Kalahari Bushmen have won so few Nobel Prizes.

  17. Max says:

    I will, however, give praise where praise is due. PHD gets that multivitamins aren’t a great idea and does not recommend them. It gets that calcium is not a great idea and doesn’t recommend it either.

    Would someone please provide support for this claim? I’m not asking because I disagree, but because I take a multivitamin and drink lots of milk. If I shouldn’t be doing these things, I’d like to know (why).

    • ozymandias says:

      I don’t know *anything* about nutrition, but this question was unanswered for a while, so I am going to answer as best I can in the hopes that this will inspire someone more qualified to correct me.

      I would predict that Scott was talking about supplementing with calcium and not about drinking milk. Consuming too much calcium is linked to various things like kidney stones and heart disease. Consuming too little calcium is linked to osteoporosis.

      There is very little evidence that multivitamins actually reduce mortality for most people. Too much of some vitamins leads to increased health problems.

      A lot of it depends on your diet. If you’re eating a varied diet, your multivitamin probably isn’t doing anything. If your diet is significantly limited in some way, you may need to look into supplementing with particular vitamins. For instance, vegans should take a B complex, because there are no vegan sources of some B vitamins.

      • Max says:

        Thanks for the response. Your advice seems to be in conflict with Scott’s, so I’d appreciate it if someone could help mediate.

        “PHD gets that multivitamins aren’t a great idea and does not recommend them.”

        vs.

        “If your diet is significantly limited in some way, you may need to look into supplementing with particular vitamins.”

        • Fnord says:

          Presumably you just want to supplement the specific vitamins that you have reasons to think you actually need.

        • ozymandias says:

          I don’t think that’s contradictory at all. Multivitamins are not a great idea for most people; taking specific vitamins you have reason to believe you need is a good idea for some specific subpopulations.

        • Max says:

          Perhaps I simply read too much into the comment. I got the impression that he was suggesting they were actively harmful and should be avoided. I’d be curious to know where the idea that they’re extraneous comes from, though, because I’ve never known a seriously competitive athlete who didn’t take one. This may be a byproduct of the fact that weight classes = weight cutting = inadequate vitamins/minerals from daily food intake, though . . .

  18. the Gell-Mann Amnesia Effect argues that if the parts you know something about are bad, you should assume the parts you don’t know enough to criticize are as well.

    Hadn’t heard of this term before, but this describes one of my breakups quite nicely. My then-partner started saying things that I knew to be absurd, but she said them with the same confidence she spoke with around subjects she was supposedly knowledgeable about (that I knew nothing about) and I was struck by a lack of ability to trust pretty much anything she said. Not because I thought that she was lying, just that I didn’t trust her epistemology.

  19. Anonymous says:

    Just for reference, here’s Mark’s Daily Apple (which I’d consider to represent the “mainstream” paleo stance) writing about potatoes.

    -http://www.marksdailyapple.com/paleo-potatoes/#axzz2v4ZfitaC
    -http://www.marksdailyapple.com/potatoes-healthy/#axzz2v4ZfitaC

    TL:DR – How much starch you can/should eat is a complicated question, but a potential problem with potatoes as a starch source is that potatoes have inflammatory glycoalkaloids, especially in the skin.

    (Also, this is actually the first time I am hearing of a “classic paleo diet” which disallows carbohydrates from things like fruits and tubers. That seems more typical of maybe Atkins?)

    • Randy M says:

      I think that would refer to Cordain’s “The Paleo Diet” which was more restrictive than MDA’s Primal or other versions.

  20. Great post, Scott. Leaves me wondering how Eliezer will react to it.

  21. Eliezer Yudkowsky says:

    I’m the guy who bought Scott the book, actually. And for those who may have been confused by connotations, it wasn’t so much, “Read this to find out why saturated fat is okay” but “Scott, you disagree with this book I used to build my ketogenic Soylent, can I buy you a copy so I can hear what you think of it?”

    I’ll need to read this post more carefully later, but two things I found surprising are that Scott recommended lithium and that he thinks selenium… shouldn’t be supplemented(?). Lithium, AFAIK, has no known chemical role in any known biologically active molecules in the human body, so I was hesitant to try lithium orotate despite PHD recommending it, because the last I heard lithium was just supposed to get in the way of synapses and possibly calm down manic people, and I wasn’t sure that was going to help information processing on net. (There’s a similar story with chromium, as Louie Helm recently posted – we don’t know of any actual metabolic process in which it plays a role, and it’s possible that the studies showing “glycemic control” are just showing that the body has to expend energy to get rid of this useless chromium contaminant.)

    On the other hand, we know that selenium plays a role in thyroid processes. And in PHD they carefully emphasized ideas like, “Okay… you can’t *just* pump up selenium because if you’re not getting the right amount of iodine that will make things worse… but you also can’t pump up iodine immediately if you don’t have enough selenium, plus that might exacerbate autoimmune disorders which in turn might be caused by gluten… so get the RDA of iodine and such-and-such selenium until you’ve been gluten-free for a month, then slowly ramp up the amount of iodine.” This sounded to me like the kind of plausible story that would account for a lot of other studies producing misleading results, especially when you take into account that PHD thinks only particular kinds of organic selenium are good for you, and inorganic forms like sodium selenite are not. Part of what I found plausible about the whole viewpoint in PHD was that things were allegedly sufficiently complicated that studies which just threw blah at blah would be expected to come up with contradictory and misleading results. Which in turn would explain why the field was in a state of despair and disrepair.

    Scott, is your judgment already taking that into account? Like, are the selenium studies failing to find good results even after using organic sources of selenium and checking that iodine is not deficient without ramping up too much iodine too fast?

    • James Babcock says:

      So, I followed up your comment with a few quick google searches, and scanned my multivitamin’s ingredients label, and found that Chromium supplements are actually Chromium picolinate. And picolinate looks anything but inert; I found quite a few claimed mechanisms by which it’d have health benefits (increasing zinc bioavailability, chelating other metals, antiviral action, protection from quinolinic acid whatever that is). I don’t have time to follow them up, but comparing Chromium to picolinic acid, if I had to bet on one or the other as an explanation for the metabolic effects, I’d bet on the picolinic acid.

      Huh, I thought. That seems odd. So I continued reading your comment, and looked up lithium orotate. Or rather, I looked up orotic acid, which according to Wikipedia “historically was believed to be part of the Vitamin B complex and was called Vitamin B13”. Further googling turned up a large morass of biochemical networks and claimed effects, some neurological. Not all lithium supplements are lithium orotate; I haven’t looked up what version the lithium effects studies were done on.

      I have no opinion on selenium as yet, but will note that while its prior is a lot better than chromium’s and lithium’s were, since it has a claimed biological mechanism, I’m questioning chromium’s and lithium’s value.

    • Anonymous says:

      Eliezer, have you had any success with this diet? As I recall, you were struggling to lose weight.

    • Scott Alexander says:

      I may be coming from a more empirical perspective than you are. I admit it’s strange that lithium is so useful when it isn’t a normal component of the human body. There are some plausible mechanisms, like lithium displacing sodium and everyone knows we have too much sodium. But I’m pretty happy with the studies in lithium’s favor and I’m sufficiently used to not having biological reality correspond to anything predictable that I’m willing to swallow it.

      The studies I have seen with selenium do mostly use organic selenium. They do not carefully monitor the iodine/selenium balance. Then again, neither do the studies that PHD cites in support of selenium having effects. If studies that did something complicated with iodine were contradicted by studies that didn’t, I would agree that it looks like optimizing selenium-iodine balance is the crucial difference. As it is, it just looks like the negative studies were better than the positive ones.

      If my understanding there is accurate, then that just leaves us at whatever our evidence-unsupported prior for their selenium-iodine theory is. My evidence-unsupported prior for anything in nutrition is very low. It is especially low with nutrient balance claims, because it is way too easy for people to find that their favorite nutrient failed to show any effects in studies and then back up to claims about nutrient balance, of which there are hundreds possible and which it is never possible to do enough studies to disprove.

      But I admit if you have a stronger prior for their selenium-iodine balance claim being correct, it has yet to be officially disproven.

  22. BenSix says:

    This guy is a formidable source of anti-paleo and low carb arguments. He has the inevitable bias of an ethical vegan but if anyone wants to challenge their ideas, he’s the man.

  23. maia says:

    Interesting thing I noticed while reading this book: They cited a study in which “83% of participants had a sensitivity to gluten.” I tracked down the study. Turns out that 83% represented 5 out of 6 participants in the study, 3 of whom had known gluten allergies and were selected for the study on that basis (or maybe had celiac, I don’t recall). >.>

    There are other potential issues with wheat though. The phytates / lectins issues seem more plausible from what I’ve seen.

  24. St. Rev says:

    Potatoes as a staple may be a problem just from the glycoalkaloid content. Superficial web search + arithmetic suggests it’s not hard to exceed the safe limit. This report seems like a legit survey, although it appears to be about 20 years old and it’s not clear when/if it was published. (Most other web references appear to be crank sites or mouse studies.)

    Having said that, it appears that a lot of the old Soviet states consume twice or more what the Irish do. That would be the place to do a population study.

    Anecdotally–which is to say, uselessly–all the nightshades appear to aggravate my Chronic Mystery Pain Disorder, although tomatoes are the worst.

    • BenSix says:

      Having said that, it appears that a lot of the old Soviet states consume twice or more what the Irish do.

      Yes. Poles emerge from shops straining under the weight of gigantic sacks of spuds. I don’t know what effects the glycoalkaloids are having but it can’t be doing their backs much good.

  25. Michael Terry says:

    Read up on everything that Stephan Guyenet has written on the Diet-Heart hypothesis and saturated fat. Here’s a random one, but he has whole series devoted to it.

    http://wholehealthsource.blogspot.com/2011/01/does-dietary-saturated-fat-increase.html

    The infamous “they” have been trying to show that saturated fat causes heart attacks for a very, very long time now, and still have not been able to do so. Imagine if this much effort and time had been put into some less politically appealing hypothesis: Would folks still be so wildly generous in giving the benefit of the doubt?

    • Randy M says:

      Why do you feel this is a politically appealing hypothesis? Anti-westernism? Veganism?

      • St. Rev says:

        Two possibilities off the top of my head:

        First, it’s not clear why, but there’s a persistent association in American crank health movements of animal foods with vice, and vegetable foods–particularly grains–with virtue. This goes back at least to the Kelloggs and their ilk in the late 19th century. Maybe a contrarian class signaling thing?

        Second, the US federal government seems to have decided in the early 1970s on a policy of pushing grain-based diets. This may have been a reaction to Erlichean limits-to-growth arguments in vogue at the time, or a top-down attempt to lower spending on food by redirecting people to cheaper calories, or a shift in the political power balance between ranchers and farmers. See for instance this on the history of federal nutrition education.

      • St. Rev says:

        Taubes traces the process through Ancel Keys’ influence in the 50s/60s and George McGovern’s Senate committee in the 70s: http://www.second-opinions.co.uk/taubes.html

        Read with several dashes of salt, of course.

  26. pwyll says:

    Thanks Scott, I’ve been looking forward to this.

    Regarding the parts of the book you felt were inaccurate and/or unsubstantiated, I’d encourage you to reach out to PHD author Paul Jaminet directly. I’ve corresponded with him in the past and I suspect you’ll find him pleasant to dialog with. I value both of your perspectives and would be very happy to see some kind of synthesis come out of this.

  27. Steve Johnson says:

    “And the Japanese remain some of the healthiest people in the world while eating rice by the bucketload, so anyone who tells you that rice is bad for you has got something like a hundred million contrary data points to overcome.”

    13.5% of adult Japanese have diabetes – better rethink those data points.

  28. Laura says:

    My question is why you would conclude that potatoes are problematic because of Irish health problems rather than concluding that Western diseases are the result of something other than the choice of starch in their diet. The Japanese are an extremely inbred and genetically and culturally narrow population. That they are healthy may have nothing to do with the choice of rice over wheat. That the Irish are unhealthy in the same ways as other westerners and don’t eat wheat suggests to me that the wheat is *not* the culprit that is making other westerners unhealthy. Yes, it could be the omega 6s, sugar, or other foods we have in common, but it could also be a combination of genetics and other lifestyle choices. Are the Irish as sedentary as Americans? Are they as overworked and stressed out? Do they spend most of their time indoors?

    My own personal experience with the paleo diet, was that while I did lose weight, my cholesterol sky-rocketed from high-end normal to 367. Attempts to eat a low sat-fat version in the diet resulted in even more dramatic weight loss (inability to maintain weight even when force-feeding self) and other health problems. All of my health problems basically disappeared after going back on what is essentially a more healthy version of the western diet- ie moderate intake of all macronutrients with emphasis on fruits, vegetables, whole grains, and low-fat dairy. I am now very skeptical of diets that take anything to an extreme, and warn people that if they feel sick on a diet, it’s not because they are ‘doing it wrong,’ or ‘not doing it enough,’ but that they should probably change strategies.