What should I have for dinner? (A case study in decision making)
Everyone knows that eating fatty foods is bad for you, that high cholesterol causes heart disease and that we should all do some more exercise so that we can lose weight. How do I know that everyone knows this? Well, for one thing, this government website tells me so:
We all know too much fat is bad for us. But we don’t always know where it’s lurking. It seems to be in so many of the things we like, so it’s sometimes difficult to know how to cut down.
...kids need to do at least 60 minutes of physical activity that gets their heart beating faster than usual. And they need to do it every day to burn off calories and prevent them storing up excess fat in the body which can lead to cancer, type 2 diabetes and heart disease.
See, it’s right there in black and white. We all know too much fat is bad for us. Except… there are a lot of people who don’t agree. Gary Taubes is one of them, His book, Good Calories Bad Calories (The Diet Delusion in the UK and Australia), sets out the case against what he calls the Dietary Fat Hypothesis for obesity and heart disease, and proposes instead the Carbohydrate Hypothesis: that both obesity and heart disease are caused by excessive consumption of refined carbohydrates, rather than dietary fat.
Taubes is very convincing. He explains how people have consistently recommended low-carb diets for weight-loss for the past 150 years. He explains how scientists roundly ignored studies that contradicted the link between high cholesterol and coronary disease. There are details of the mechanism by which eating refined carbohydrate affects insulin production, leading to obesity. He gives a plausible narrative for how the Dietary Fat Hypothesis came to be accepted scientific wisdom despite not actually being true (or supported by the majority of the evidence). He explains how studies of low-fat diets simply ignored overall mortality rates, reporting only deaths from heart disease, and how one study wasn’t published because ‘we weren’t happy with the way it turned out’. All in all, the book is very convincing.
I expect a relatively large percentage of people on LW are already aware of this. Searching the LW archives for ‘Taubes’ gives several, mostly positive, references to his work (Eliezer seems to be convinced “Dietary scientists ignoring their own experimental evidence have killed millions and condemned hundreds of millions more to obesity with high-fructose corn syrup.”). However, I do expect it to be news to some people, and I think it raises an important question. Given that everyone needs to eat something, we all need to decide whether we believe Taubes or whether we believe Change 4 Life.
Good Calories, Bad Calories is 601 pages of relatively small type, and contains 111 pages of references. Most of you probably don’t want to read a book that long, and you definitely don’t want to check all of it’s references. Even if you did, Taubes openly admits that his book is attempting to argue for the Carbohydrate Hypothesis—he is trying to convince you, why should you be surprised if you find yourself convinced? (He claims not to be cherry-picking but then, he would, wouldn’t he?) So how can you decide whether to trust the government or whether to trust some journalist with no training in biology? Even if you do decide to assess the evidence for yourself, how exactly should you go about it?
This is the key question of rationality. How can we believe what is true? And I think this makes a great case study—it’s an area in which we all have to have a belief (or at least, act as though we have a belief) and one in which there is (or at least appears to be) genuine controversy as to what is true and what is not.
If you’ve already thought about this, do you believe Taubes’ thesis, and how did you come to this conclusion? If this is the first time you’ve ever heard of Taubes, how far have you shifted your probability for the Dietary Fat Hypothesis based on reading this post? What more research do you intend to do to decide whether or not to continue believing it? How much weight do you place on the fact that I believe Taubes? On the fact that Eliezer believes Taubes (Eliezer, if your position is more nuanced than this, feel free to correct me)? How much did you update your beliefs based on what other commentors have said (assuming there have been any)?
I am an obesity researcher and I think that in some sense the idea that we are programmed to eat and to store fat for lean days is correct, and that our current environment of abundance combines with this innate tendency to increase the prevalence of obesity. But this general statement hides many unknowns. For example, why are some people more prone to weight gain than others (in the same environment)? Why is obesity heritable (20-80% heritable depending on how you calculate it and the population you use)? Taubes is absolutely correct in stating that the “low-fat diet” mantra was promoted without any evidence to back it up and the evidence we do have seems to favor low-carb diets, at least in the short run. Fructose (and its not just high fructose corn syrup...sucrose is 50% fructose, HFCS is 55% fructose) does indeed seem to be deleterious above and beyond just adding calories, but its not the whole story either. Toxins and endocrine disruptors may play a role, but we really dont know too much about that yet. Bottom line: the notion that we know NOTHING about nutrition is false. But the notion that we know all we need to know about diets and obesity is also false. The notion that higher carb intake is responsible for most of our increased weight gain is plausible (supported by data about total carb intake in the population..its the only macronutrient that has actually increased in per capita consumption. Fat intake has declined in the last 30 years, yet weight gain has accelerated) but not the whole story either. Its also worth keeping in mind that there is no one-to-one correlation between obesity and particular disease outcomes (diabetes, heart disease). On a public health level, there is an increased risk, but there are a very large number of “healthy obese” people; there is good evidence that modestly obese adults trying to lose weight have higher mortality than those whose weight remains static or slightly increases; there is very good evidence that most diets and other prescriptions dont work and lead to yo-yo weight change that may itself be unhealthier than the baseline moderate obesity; there is good evidence that lack of fitness is a far more significant risk factor for morbidity and mortality than BMI (in adults), and so on....the “moral panic” about obesity is not always grounded in sound science. “Prevention of obesity” by focusing on weight gain in children may bypass some of these concerns, but we have to be careful to see if we are responding to a fashionable moral panic or focusing on truly evidence-based fears AND interventions (even if the fears are real, all responses are not automatically justified; some responses to the disease may be worse than the original disease, others may be ineffective and hence a waste of time and money)?
Awesome comment, I really do wish you would use more paragraphs :)
You make a lot of interesting points, but how do you apply them to the question at hand: what should you have for dinner, and why?
I’ve heard this claim often, and I appreciate your pointing out that sucrose is hardly better than HCFS.
What evidence is there for human health being improved by avoiding fructose (on the margin, not absolutely)? Isn’t it pretty weak? There are plenty of high-dose rat studies, but I don’t typically adjust my lifestyle every time a rat study shows something.
I think you may want to look at the fact that glucose can enter the blood stream and be used as glucose by muscle/brain/other tissues. Fructose does not leave the liver as glucose does but is trapped there. It is used by the liver to make glycogen and when glycogen is not needed it is used to make triglyeride fats in LDL cholesterol packets. Much, much more of the fructose goes into storage molecules then into immediate energy use by tissues compared to glucose.
Fructose also creates problems in the gut.
Sucrose is less soluble and so less can be used for sweeting drinks etc. More fructose can be used with HFCS.
That sounds reasonable. I’ve heard that glycogen is stored in proximity to muscle for fuel, and if you do a lot of work (e.g. a long walk) any available glycogen is used to replenish those stores. That is, the only time it’s reasonable to gorge on carbs (which in practice always means some fructose) is when you’ve somewhat depleted your muscle glycogen.
There are human studies as well on fructose showing that it causes problems, one of which is obesity (but other problems like liver scarring are more serious). I am not going to include citations but if you go to ScienceDaily news and search on fructose you will find the latest research.
I’ve never heard this before, can you provide some links/references for more info please?
Here are the food heuristics I like to use:
Variety, variety, variety. I don’t always succeed at this when I’m not in full control of my food purchases or fall into a rut. But eating many different things is likely to capture more of the nutrients I need than eating just a few things.
If something tastes better than it usually tastes, or seems more appealing than it usually does, eat it until it stops doing that. Flavors aren’t static things that only signal what’s in a food—they are also somewhat responsive to the body’s needs.
Exception to the above: If I eat a lot of something and the craving doesn’t let up, it’s probably not actually helping, it’s just a stand-in for something nearby in foodspace that I actually need. At this time it’s better to think of what it might stand in for. Really persistent legume cravings tend to go away more readily if I eat fish; if I want fruit more than usual it can mean I’m thirsty.
Remember that food does not lose nutritional value if you add things to it. For example, broccoli is not deprived of the broccoli-nature by the addition of cheese. It’s still broccoli and still contains all the goodies it contained before it was doused with dairy.
Supplement key nutrients that my diet may not cover. For instance, I crisp up in the sun and therefore avoid it—I take vitamin D. I have a history of anemia—I take iron.
In fact, adding fats to veggies may make the vitamins in them more accessible for your body.
Not unless your diet has a huge amount of iron, it won’t.
Are trying to encourage us to eat paperclips now?
No! That’s sick!
What I mean is, if you’re going to do something as wasteful as eating, you might as well eat the kinds of things that will seed your body with iron so that it’s easier to extract after you’re uploaded.
Speaking of uploading, Clippy, how would you feel about tiling the universe with paperclips that could each be one of two colors and changed color depending on certain algorithms and the behavior of their neighboring paperclips?
I think that’s great! Color doesn’t matter (glares at humanity) as long as the spectral readings still show the paperclips to be sufficiently metal.
By the way, I know where you’re going with this, and it just shows you to be much closer to me, inferential-distance-wise, than most of the humans here. I need to explain much more to these humans before I can make the argument you’re leading up to.
I’ve long recognized you to be much more enlightened than most of the humans here, ever since you pointed out the subtle racism they practice—it’s the other Users I worry about.
What’s the smallest object you’d consider to be a paperclip?
It has to be able to (counterfactually) hold several sheets of paper together without permanent deformation of the clip, and without significant deformation of the paper. Exactly how many sheets? Exactly how much paper deformation? I’m still figuring it out for myself, but that should give you some idea.
So, considerably larger than the semi-conductors used in computers. The paperclips could be shrunken somewhat by developing the thinnest possible paper, but the results would still be nowhere near current systems.
You could get better results (by human standards) by having very small changeable color areas on each paperclip.
You know what?? first i thought i knew what was going on… and then i was confused, and then i created a few new theories, and then i was confused again. This really bugs me… It sounded like you were referencing the game of life, but i cannot comprehend the connection to paperclips. Alicorn, if that IS your real name, you are a froody dude. now stop making my life surreal.
Clippy is a user who reports to be a paperclip maximizer, a hypothetical AI that only cares about increasing the number of paperclips in the world. See paperclip maximizer for more details. Many users suspect that Clippy is meant to be humorous but it does bring up serious questions about how one can cooperate with entities that have goals which are radically different from human standard goals.
LW is a very weird place.
“I really like paperclips” is the connection.
Well, that makes sense now. As long as your utility function does not in some way involve the use of proprietary software or pre-built computers then our utility functions should not conflict in the near future. Of course, the connection between your name and a certain Microsoft product does inspire revulsion, but changing it would not advance my utility in any way. /me orders robot minions to return to collecting minerals and vespene gas for the final assault on apple headquarters.
This is the first time in months that I’ve sincerely wished to upvote a comment more than once. Thank you, Alicorn, I knew you would deliver. I’m sitting here staring at my monitor, across the ocean from most of LW, and can’t stop laughing.
Was User:Alicorn being non-serious with that comment?
I did it for you. At least you are on the same side of the ocean with all the other LW Vladimirs ;)
this might just be the single greatest comment I’ve seen on LW.
This could be the first sign of converging utility functions. I never thought I’d say this, since it defeats the whole point, but perhaps Clippy and I aren’t that different after all.
Umm, iron. Wonder what I could do with all that body iron...
As CronoDAS has pointed out, the field of nutrition science has a long history of releasing bad studies leading to conclusions that were later proven false. Here are some of the stupid things which researchers have done, which have lead to bad dietary advice:
Inferring what’s good or bad for humans from its effect on lab rats
Studying a diet’s effect on one particular disease, then using it to argue for its effects on overall health
Conducting a controlled study, losing half the sample to dropouts and non-compliance, and pretending that the group that dropped out did so for a reason other than because the diet was hurting them
Measuring weight loss, but failing to distinguish between loss of fat and loss of muscle.
I believe Taubes is correct, and that the idea that low-fat diets are healthy is due to errors 3 and 4. What convinced me was hearing a bodybuilder talk about fat and muscle weight as separate things, and connecting that observation to the “rebound effect”—that is, the observation that people who lose weight on low-fat diets tend to gain it back plus extra. My interpretation of this is that some of the weight they lose is muscle, not fat, and this lowers their metabolism. This makes sense because maintaining muscle requires protein, and low-fat diets are usually also low-protein diets; the most common protein-rich foods, meat and eggs, are also high in fat.
This also explains why vegetarians don’t have the same problem with low-fat diets: they’re specifically instructed to be careful about their protein intake.
jimrandomh:
You forgot:
(5) Conducting a more or less decent controlled study, and then releasing a popular version of the results to be carried by the press and proselytized by various quasi-experts, busybodies, politicians, and bureaucrats, in which a tendency observed merely as a statistical phenomenon in the given sample is presented as a universal rule applicable to each single human individual.
That almost goes without saying.
Great post. Since I have had (a diluted form of) the position Taubes describes for a long time (since before I was exposed to OvercomingBias, much less LessWrong) I cannot speak too much about the influences from here but it is a useful exercise to to try to trace how I update my beliefs in practice.
Caveat: I know damn well that I suck at giving true reports on what really causes me to change my mind. Our self awareness isn’t particularly motivated to be honest about such things. Nevertheless I can give a best estimate on what influenced me.
Yes. From what I can tell I formed the belief based on exposure to various experts that appeared to be Correct Contrarians. As someone who has taken an interest in a whole range of topics regarding health I have been exposed to experts in all sorts of fields that overlap with nutrition. It is not hard to distinguish between experts that seek out research to form accurate opinions and ‘experts’ who specialise in presenting authoritative beliefs. It is also not hard (given the right skillset) to independently verify the positions of such experts on their core positions. Basically none of those individuals support the idea that fat is the big culprit or a worse health risk than carbohydrate.
I know little about Taubes. I’ve seen him as a reference but most of my exposure has been to other authors.
Probably quite a lot. ie. I am currently studying pharmacology degree with the intent of doing research in loosely related areas. I will almost certainly learn more about that kind of nutrition so as to better understand my own specific topics of interest.
A moderate amount. Your presentation is credible and any report from an evidently educated reader that demonstrates an interest in epistemic knowledge and an understanding of bias carries weight.
Hmm. Eliezer does seem to be good at identifying correct contrarians so his position on such topics carries some weight. What carries even more weight is when Robin and Eliezer both support the same position—they have sufficiently different influences that agreement counts for something. I don’t recall whether Robin has blogged about diet advice in particular but his writing on health topics in general give credence to this position either way.
To be honest probably not much. I participate in other forums with a much higher level of knowledge on this area. On health related topics where I have been disagreement with other commenters here I have updated far less than when I have disagreed on non-health topics.
Which forums?
ETA: You probably refer to Imminst.org, right?
Imminst is a good one. There are others that also have more knowledge but less callibration.
My conclusion has been: nobody really knows anything about nutrition, so I’m going to eat what I damn well please. (They used to say that margarine was better than butter, but now they’ve concluded that “trans fat” is actually worse than ordinary saturated fat.) Summing up all the various advice, it all seems to come down to “eating is bad for you.” (And data on caloric restriction seems to confirm this!)
Remember this scene from Woody Allen’s movie Sleeper?
That’s a tempting conclusion but not a rational one. I know, for example, that:
If people don’t eat things containing vitamin C their teeth will fall out.
People who live underground or, say, near one of the poles, need to consume more vitamin D.
Drinking a bottle of undiluted cordial when you are diabetic will probably damage you.
Living on a diet of almost entirely maize will give you dementia (and assorted other bodily symptoms up to and including death) due to Niacin deficiency. Consuming a large dose of Niacin will totally freak you out unless you know what to expect. Your skin will flush and hurt like hell but fortunately be doing far less damage than it may appear.
There are 8 amino acids that humans need to consume in their diet. Failure to consume these amino acids can cause things like Kwashiorkor.
Point taken—“nothing at all” is certainly an exaggeration—but most people in the United States don’t suffer from acute micronutrient deficiency (or amino acid deficiency).
Incidentally, another bit of “conventional wisdom” that’s been overturned, along the lines of the butter/margarine reversal: according to controlled studies, large doses of antioxidants reduces life expectancy. And by “antioxidants” I mostly mean vitamin E:
Source.
This does make you wonder just what on earth people were thinking when they thought extremely large doses of something fat soluble was a good idea. Crazy. I am somewhat wary of saying ‘large doses of antioxidants reduces life expectancy’… that seems to be completely the wrong inference to make. Melatonin is a far stronger anti-oxidant than vitamin E but ridiculously high doses of melatonin don’t cause the same problem. (By ridiculously high I refer to levels of antioxidising power that would require easily fatal levels of vitamin E to achieve.) Why don’t they try the generalisation “large doses of fat soluble vitamins”? That’s far more credible.
/me shrugs
I don’t really know all the details, but “Eat this because it has antioxidants, which are good for you” still seems like a bit of a lie...
Good point.
You’re quoting fictional evidence. I’m afraid you’ve bought a media narrative that’s almost entirely at odds with the truth. I strongly recommend Ben Goldacre’s book Bad Science for more on this: healthy eating advice has stayed roughly the same for decades.
The “Sleeper” quote was a joke. :(
Great case study, in that studying my own reaction to your article has thought me a lot about my own decision making. And my conclusion is that reading a rationalist blog isn’t sufficient to become rational!
I am thin, despite having very bad eating habits (according to conventional dietary wisdom). I had not heard of Taubes before. Specifically, I have never considered that conventional dietary wisdom could be incorrect; people say that I eat unhealthily, and I have simply taken their word for it. The fact that I continue to eat unhealthily has more to do with laziness than rationality.
How much have I shifted my beliefs now that I have read this article? I don’t think in probabilities yet, but… by a lot. Probably more than I should. Neither Taubes’ belief nor bentarm’s belief nor Eliezer’s belief nor Taubes’ lack of biological credentials has affected my own degree of belief, not by much anyway. Just the fact that there exists an alternative theory of food has succeeded in demolishing the confidence I had in the conventional theory.
How could such a weak amount of evidence cause such a large shift? By relying on a bias which happened to be pushing in the same direction. Just ask me: “since you have decreased your belief in the conventional theory after reading an article on Taubes, you must have correspondingly increased your belief in Taubes’ theory, right?”
Well, let me google whether the fatty food I currently eat is high-carb or low-carb, and I’ll get back to you on that.
It is rational to update by a lot in response to a small amount of evidence if that evidence brings along a possibility you hadn’t considered before, that possibility has a high prior probability, and you didn’t have much evidence to begin with.
This is a fascinating topic, and I hope it attracts more commentary. As Bentarm says, it is important and relevant to each of us, yet the topic is fraught with uncertainty, and it is expensive to try to reduce the uncertainty.
I do not believe Taubes. No one book can outweigh the millions of pages of scientific research which have led to the current consensus in the field. Taubes is polemical, argumentative, biased, and one-sided in his presentation. He makes no pretense of offering an objective weighing of the evidence for and against various nutritional hypotheses. He is selling a point of view, plain and simple. No doubt he felt such a forceful approach was necessary given the enormous odds he faces in trying to gain a hearing for his ideas. But the fact remains that the reader must keep in mind that he is only hearing one side of the story.
Weighed against Taubes (and others who have advocated similar positions) we must consider the entire scientific establishment, thousands of researchers who dedicate their lives to the pursuit of knowledge. To believe Taubes, we must believe that these people are basing their entire professional careers on a foundation of falsehoods. Worse, from the lack of impact Taubes’ book has had on consensus opinion, we have to imagine that researchers are willfully ignoring the truths that Taubes so convincingly reveals. Nutrition researchers are intentionally lying and covering up the truth in order to protect the false dogma of the field. (Note that this is exactly the same critique of researchers made by global warming skeptics.)
I can’t believe that scientists are so dishonest, or that such a cover-up could be executed successfully. I can’t imagine how any young, budding nutrition researcher could go to work in a post-Taubes world with a clean conscience, if the book is really as convincing as it claims to be.
My conclusion is that to someone intimately acquainted with the field, Taubes’ book is not as persuasive as it appears to the layman.
Now, I will confess that I have some independent reasons to doubt Taubes. But I would prefer not to go into that because IMO the argument I have outlined above is sufficient. Never believe a polemical, one-sided book which has been rejected by the scientific establishment. I offer that as a valid heuristic which has proven correct in the overwhelming majority of cases.
I roughly buy this argument. However, I’d be interested to know more about how you distinguish this from the rejection of cryonics by cryobiologists.
One problem with all these debates about nutrition and exercise is that they mostly don’t take into account individual differences. How exactly your body will react to a certain regime of diet and exercise, and which regimes are compatible with reaching and maintaining your optimal weight while feeling good and healthy—the correct answers to these questions depend very strongly on your genotype, and possibly also on a number of entirely non-obvious and unknown environmental and lifestyle factors. (And to make things especially un-PC, the relevant genetic factors seem to correlate strongly with ethnic origin, since they’ve evolved significantly during the last few thousand years. This has been proven conclusively only for a few things like lactose tolerance, but it seems quite plausible that analogous group differences exist for other nutrients too.)
Therefore, except for a few simple observations like e.g. that you need some vitamin C to avoid scurvy, promoting certain diet guidelines as universally valid for all humans can’t be other than nonsense. It’s similar to those silly government propaganda campaigns about “safe” drinking limits that supposedly hold for everyone, whereas in reality, some people can drink a bottle of whiskey a day and nevertheless live long and productive lives (and never even appear visibly drunk), while others would be killed sooner or later by a fraction of that—and yet others suffer from complete alcohol intolerance and get sick even from a single drink. Similarly, I have no doubt that some people exist for whom carbohydrates are as bad as Taubes says, but I also have no doubt that for many others, his claims are exaggerated to the point of nonsense, and I strongly suspect that the latter group includes a great majority of individuals in at least some ethnic groups.
As the bottom line, until scientists gain a much better understanding of the genetic and other factors involved, there really is no good way to go except self-experimentation. The only time I got into such a bad shape that I had to lose weight, I managed to devise a regime that enabled me to lose a pound a week with only a small expense of willpower, which was however completely unlike anything I’ve ever read from any side in the diet/exercise controversies—and I doubt it would work for very many other people.
Exactly. The “Typical body fallacy”.
Please tell me more!
If you’re in the market for idiosyncratic weight-loss anecdotes: I lost 30 pounds in a month by having a stroke and spending that month in a rehab center with right-side hemiplegia, then another 20 over the next three months or so on a diet that was 90% homemade soup and roasted vegetables, with a scheduled Indulgence Night every few weeks where I went out and ate whatever the hell I wanted.
I’ve since then gained about half of that weight back by eating out more often.
I put high levels of trust in my own repeated experience, and even moderately low fat eating leaves me feeling lousy within a day or less. This inclines me to believe that Taubes is on to something. And that people who push extreme low fat may mostly like the drama of aesceticism.
On the other hand, there are people who tolerate low fat diets much better than I do, and my general assumption is that people’s dietary needs vary a fair amount.
My theory (which I don’t follow consistently) is that people will do pretty well if they eat according to what will leave them feeling good three or four hours later. Some people with food sensitivities need to be thinking 2 or 3 days ahead—sometimes it can take that long for a migraine to show up.
I realize that my theory has a bunch of caveats—I seem to notice how I feel more than most people do. I like enough variety in my food that I have a chance to find out how different things make me feel. which, again, isn’t most people’s default.
I’m not going to trust anyone’s theories about food unless it at least has some overlap with my experience.
Agreed. I optimize my diet for effects on short time scales. There seems to be a lot of evidence that the diet I’ve arrived at is also optimized for long term health, but, honestly, I would eat the way I do even if I knew it would reduce my lifespan by a decade. My diet has improved my quality of life too much for me to give it up.
Piling on, here is Alone on diet studies:
“A glance at the methodology has more practical value than the little asterisk above a score at month 6.”—regarding the uselessness and distraction of p-values.
“the purpose of these studies is not to determine the answer, the purpose of these studies is to be published”
That’s actually a recurring theme in his posts. In this one he analyses the methodology of a study on a Bipolar Disorder drug. Conclusion—the authors claim the study shows that the drug is 50% more effective than a placebo. What the study actually shows, when one looks at the methodology, is that among people who responded well to the drug, 50% of them suffered relapse when the drug was discontinued. This is not surprising. And it doesn’t say what the actual efficacy of the drug is at all.
Another reason diet is a good case study is that people can become very emotionally invested in their diets. Vegetarians and vegans, of course, have moral reasons, but even people with no moral reason for their abnormal diet can become incredibly defensive.
Raw foodists, paleo, low carb, high carb, organic. It’s amazing to see people argue and defend incredibly poorly thought out ideas, sometimes very passionately. I’m mostly paleo myself, but I have to shake my head at a lot of the arguments and defenses I see put forth from the paleo community.
We like to say that religion and politics are mind killers. In my experience diet can be just as much so. I was actually in the process of writing a top level post about this. I’m glad this post is getting so much love though. Now I can be lazy =D
I have not read Taubes but I do read almost all the announcements on nutrition science that hit reviews like ScienceDaily etc. From what you have said of him, I probably would agree with him. I find main stream nutritional science to be tawdy if not positively dishonest. My view on fat is: trans fats are very dangerous, way too much fat is dangerous, way too little is more dangerous, cholesterol is important but dietary cholesterol is not as important (if you eat lots than the body makes less and vice versa), essential fatty acids are really essential and you will suffer without them, forget about the fat it them and like your grandmother believe that milk and eggs are great food, you need fat soluble vitamins. In general, metabolism is a very regulated feedback system. Obesity is not about the number of calories you take in. It is about how much food, which kind of food, how much exercise, what kind of exercise, gender, age, genetic makeup, poisons/disease. Carbohydrates can be made from fat and fat can be made from carbohydrate. The way to get too thin people to gain weight is not to feed them more but to alternate dieting with not dieting. I live in France where people tend to be thin. They eat very, very well and lots. They eat fatty and protein-heavy foods. They eat all the good things: garlic, red wine, fish, fruit. They eat less carbohydrate than most Western countries. I am borderline diabetic and hence my interest in this subject.
Not in animals including humans.
Yes, you are right. Carbohydrates can not be made from fat. Fatty acid are used to supply energy directly and not by being converted to carbohydrate first. Sorry to have been misleading. Thank you for the correction.
I consider myself a life extensionist and I actually found Overcoming Bias and this community via the ImmInst forums. I’ve read a lot about nutrition back then (2008-2009). As I can tell, so far the only guy besides me who mentioned ImmInst on LW is wedrifid. ImmInst remained my primary source of health info and I also frequently search pubmed for abstracts.
I haven’t read Taubes’ book. I remember faintly though that several people who disagree with the mainstream lipid hypothesis criticized the book for having very sketchy science. Its conclusions, however, seem to point in a good general direction, from what I heard. It is important to note that the “mainstream’” Taubes is against is actually very poorly established and is not something you would call solid. Why it gained momentum decades ago and haven’t already collapsed in billowing smoke is a genuine mystery of our times.
I personally follow a quite carefully constructed lowish-carb diet that I tweaked over the course of the last two years, and I also take some supplements that I also researched on the net to death. I’m not really expanding my views on nutrition right now because it’d be a bit lengthy. There are several big low-hanging fruits (like vitamin d3, one that I plan to write about a top-level post here sometimes) in life extension but most of the time it is rather like a battleground of dozens of complex and ambiguous ideas.
The issue is that it requires a huge initial effort to get a rough picture about health topics, and it also requires a considerable amount of rationality to just avoid instantly going astray and settling with some snake oil, fad diet or piece of ancient wisdom. After this barrier is overcome it isn’t very costly to maintain a lifestyle roughly optimized for health, according to what current science really says.
I’ve never read Taubes, but I share similar ideas. How did I arrive at my beliefs?
I read a lot. I try and judge the caliber of the writer. Of course, there are idiots on both sides of every argument, but I often find that one side has a preponderance of open minded, rational, reasonable supporters. Intuitively, when the evidence isn’t on your side you tend to resort to less savory tactics to win. I’ve found a lot of very undogmatic, well spoken people on Taube’s general side of the fence.
I find many of the paleo arguments convincing (although not as convincing as most people in the paleo community).
I’ve experimented heavily with my own diet. I simply select the diet that makes me feel best. I make small tweaks constantly and big tweaks rarely (sort of a simulated annealing type algorithm). I keep the tweaks that make me feel better. My current diet would pass for paleo, although it wouldn’t be typical.
Ultimately, I still don’t have incredibly high confidence that I’m right. I’d love to see some reform in the nutritional science community. I’d love to see more studies. I’d love self experimentation to become the norm, so that we could all share experiences and have a reason to encourage scientists to do more diverse studies.
Is there anything wrong with the hypothesis: I should eat foods that appear to correlate with a short-term feeling for me of improved health? Obviously you shouldn’t just eat whatever tastes good, because the economy is clogged with artificially designed superstimuli, but to my knowledge nobody is making thing that make you feel healthy yet aren’t.
I’ve already thought about this, and I believe Taubes’ thesis.
I came across the idea after reading about Seth Roberts experiments with eating more fats, and looked into it a bit.
I ended up changing my diet around quite a bit (almost no carbs) and have noticed quite a bit of short term improvements.
I’d be interested to see a survey along the lines of my survey of anti-cryonics writing.
I once read a great quotation, which unfortunately I can no longer find (so I understand if you vote this comment down for spreading rumours), from a person involved in the anti-fat movement (AHA, USDA, or something like that). The quoted person said that they knew perfectly well that which fats one eats is far more important than how much fat one eats, but that saying ‘Make saturated fat [and trans fats, but this was before people talked about that] a low proportion of your total fat intake.’ was too complicated a message for the public to understand, so it was better to use the less accurate but more easily grasped rule ‘Make fat a low proportion of your total calorie intake.’. (The article did not explain why the second rule would be easier to follow. It is easier using current nutrition labels, at least in the U.S., but that’s the anti-fat movement’s own fault!)
Also, the anti-fat argument was originally against heart disease, not obesity. Saturated fats (and trans fats) seem to contribute to heart disease, not to obesity. (Of course, obesity also contributes to heart disease.) The main diet-related contribution to obesity is simply total calories, for obvious reasons. Fixing the number of calories, a high-fat diet can actually be helpful (when the issue is obesity), since fats do a better job than carbohydrates of making one feel satiated. The idea that ‘Eating fats makes you fat.’ appeals to people, but it’s a fallacy that I’ve never heard from any authority more sophisticated than a fast-food commercial.
I eat a mostly vegetarian diet, for mostly ethical reasons (which are as much about the environmental impact than animal rights). But I don’t try to avoid fats. On the contrary, oils and nuts are a big part of my diet, and I wouldn’t have it any other way. Otherwise, I’d be hungry all the time!
The one that’s right out in public is the way people keep saying that there’s evidence [1] that one glass of wine per day is healthier than not drinking, but that doesn’t mean anyone should start drinking.
[1] The evidence might not be as sound as it looks. People who have one drink per day presumably aren’t alcoholics and are extremely unlikely to be ex-alcoholics, so that’s a healthier cohort than the whole population even if one drink per day doesn’t do anything to improve health.
Alcohol is probably the worst example of a health issue where all sorts of people—including numerous official “experts” with lofty titles and credentials—obsessively insist on one or another set of recommendations that are supposed to be valid for everyone, while completely ignoring the enormous relevant variation between individuals. Consequently, the claims commonly heard in public about this topic are almost pure nonsense.
In reality, depending on your genotype, a glass of wine a day can have very different effects. If you’re exceptionally alcohol-intolerant, it may cause acute poisoning, and if you’re exceptionally prone to alcoholism, it’s a good idea to stay off booze completely. On the other hand, for some people it’s perfectly safe to drink several liters of beer or wine (or a whole bottle of hard liquor) every day—they can do it for decades without ever appearing visibly drunk, and live to ripe old age until something entirely unrelated kills them. Most people are somewhere in-between, of course, but there is definitely no such thing as a universally valid limit for safe drinking. (Not to even get into the complex and non-obvious lifestyle factors that further complicate individual reactions to various levels of drinking.)
Considering all this enormous individual variation, it’s absurdly silly to give any universal recommendations about whether a certain level of drinking is on the net positive or negative. It’s as stupid as if someone tried to come up with a recommended shoe size for everyone without taking into account individual differences in foot size. (And to make things exceptionally un-PC and thus difficult to discuss meaningfully in public, alcohol tolerance appears to have been a subject of very recent evolution, and therefore correlates significantly with ethnicity. In this regard, it’s similar to lactose tolerance.)
Interesting distinction—I suppose I was expecting that if it weren’t for prejudice against alcohol, the experts would be taking those studies and saying that everyone should have one drink per day, even if what I said was more reasonable.
In a sane world, the experts would be saying something more like “Try out one drink per day if it seems to make sense for you.”
Or “Whatever, one drink is going to make barely any difference spend your attention on things that may actually matter.”
But it isn’t even remotely evident that saturated fats contribute to heart disease. There isn’t much room to rhetorically redeem a statement positing that it is.
When people talk about diet, the phrasing often seems to be “fats are bad for you” versus “carbs are bad for you” or “this is bad for you” versus “that is bad for you.”
The question that I came up with while reading this post was, why are these hypotheses in conflict? Why should there be an option that is “good for you”? Assuming that “eating” evolved by way of “things that eat tend to reproduce more” and “things that feel good when eating things that help them reproduce will eat them, feel good, and reproduce” (I realize that I’m abusing evolutionary explanations here but I will get to my point) I don’t see any reason to believe that there exists a diet which will make people happy and healthy over the long long term.
On the one hand, the existence of food that would keep humans healthy significantly past reproductive age has only been selected for in the past 10,000 years. On the other hand humans that stay healthy past reproductive age have never been selected for (at least in men ).
So there’s a lot of evidence that I don’t fully understand in the background of this debate, and I have little to no knowledge of nutrition, so I’m hoping to learn a lot and change my mind at least twice based on replies, but...
I don’t see any a priori reason that there should be a “healthy diet” that promotes longevity in the way that I would like to promote my own longevity
This makes it easy for me to agree with hypotheses like “food X is bad for you”
People seem to take sides a lot in nutrition debates; I am curious how much the science is divisive versus the discussion being divisive.
So I guess my question is, do “mainstream” nutritionists maintain that carbs are good for you? Does Taubes maintain that fat is good for you? Does data suggest that there exists a diet which is good for you, that creates serious improvements in longevity and health?
Unless all food is always exactly equally bad and nutritional science completely worthless there must be some food or combination of foods that is less bad in a given situation than the alternatives. You might as well call that food “good” since, unless identical, compared to a baseline of whatever foods would be considered the default it should have a positive effect of some kind.
I agree that good food by that definition is likely to exist, but since I don’t see a specific reason for it a priori, I don’t see any reason that the difference in health should be particularly large. One thing that I would like to see is some scientific evidence rather than anecdotal that there is any significant correlation between certain diets and health outcomes. I believe they exist but I don’t currently have strong evidence for that belief, other than “people talk about it like it’s true.”
Do the discussions change materially if we replace ‘good for you’ with some operational definition like ‘reduces problems like obesity or heart disease compared to the previous diet’ or ‘gives health results more akin to farmers in Okinawa’?
There may be no ‘healthy diet’ in some idealistic sense, but what on earth makes one think that there are not less and more healthy diets?
Considering the case discussed in the original piece, that heart disease is reduced but overall mortality isn’t by avoiding fats, then this may actually be healthy in the context you describe rather than unhealthy.
So I would say it does materially change the discussion, if not in a particularly deep way.
This is a flat-out misunderstanding of human history. The existence of female menopause, plus substantial evidence from existing hunter-gatherer tribes, suggest that longevity is adaptive. In tribes studied, post-menopausal women gather far, far more than their daily calorie intake, helping their descendants by providing extra resources. The reason prehistoric man had a low life expectancy is more due to high infant mortality than dying early. If long lives were not evolutionarily relevant, the existence of human menopause makes even less sense than it currently does.
Menopause makes sense the way I’ve heard it explained. Being pregnant, or having a young dependent child, reduces the ability to care for preexisting children. This is so obvious in resource-poor cultures that infanticide (preferentially of weak or closely spaced children) has been commonplace through much of history. The drain on resources that a new child represents increases with age: it is easier and less costly to have a child while young. After a certain point, the expected extra descendants gained by the ability to bear more babies is less than the expected extra descendants gained by investing the pregnancy & subsequent resources instead in the last one(s) born.
That’s the story I’ve heard too. I wonder just how many women in the relevant resource poor cultures aged long enough for it to matter.
That’s the exact point. Menopause is very rare in the animal kingdom. The fact that it exists in humans shows that some portion of our ancestors lived long enough for it to be selected for to the point of total dominance in the population.
That’s true.
The “don’t bother with children when you are old” incentive is also helped along by the decreasing genetic value of children born to old mothers. The likelyhood of Down Syndrome is increased by an order of magnitude or two, for example.
I would like this whole comment thread a lot more if anyone linked to any studies or at least blog posts or books on amazon or something detailing where they got their ideas from (I don’t mean to be picking on anyone I just have very little knowledge of the subject and I’m curious where people got their first notions of things like “there exists a good diet which will make people feel healthier and live longer by a significant margin”)
My source is a book, and thus not terribly accessible. As Alicorn points out, menopause makes sense, but its existence strongly suggests enough women lived long enough for it to actually be selected for. It is not common in other animals.
A very important topic.
About the topic itself, I read advice from body builders, tried it out myself and it suits me well (always with exercise included) I ordered Tom Venuto’s Burn the Fat-Feed the Muscle which went into a causal explanation of why people drop off diets and what to do about it.
Prominent points
Mental techniques are an important part of losing weight.
Loss of muscle is a big no for maintaining fitness.
Small balanced meals spread throughout the day. Bias towards protein, but all macronutrients are to be included. Try to stick to natural foods as much as possible.
Aerobic exercise and strength training have to be done to maintain fitness (sorry for bringing this into a diet thread, but the issues of diet and exercise for fitness are quite inseperable). In venuto’s words, It is better to burn the fat than attempt to starve the fat.
Cheat meals once in a week to relax your stretched willpower
The Meta-topic about how to make up our mind about this.
I would actually ask people who have to keep it real. People who have to be fit. But the issue with atheletes, models or military is that they have a lot of time to devote to themselves which normal people may not.
Your best bet may be asking people who take part in fitness compettitions as amateurs. They have real lives and have things to go back to. What they can do, you can do.
Try things out yourself, note your results and give any new experiment atleast 3 months sincerely. Since most body transformation programs are in that range, there must be measurable results in 3 months. Infact, in venuto’s own words, he tried almost everything till he settled down on his present program.
Semi-random thought:
I think that my current antidepressant medication (Venlafaxine) gave me a sweet tooth; shortly after beginning to take it, I wanted sweets much more than I used to, and the effect hasn’t subsided. (My mom says that many psychoactive medications tend to cause weight gain.)
Have you considered Stevia (Rebaudioside A) as a solution?
For what? I don’t mind having a sweet tooth. I have gained a small amount of weight over the past 10 years, but it hasn’t been too dramatic...
Sorry, misinterpreted the sweet tooth mentioned together with weight gain as a potential issue. My wrong.
I never noticed myself getting a sweet tooth when I was on Venlafaxine but your mom is right about effect of many psychoactive medications. Mind you she would be more right if she limited the claim somewhat… amphetamines have rather the opposite effect!
This post appears to lump Coke together with wholemeal rice and margarine together with extra-virgin olive oil, which I’m not sure makes much sense.
Not true at all. There are a thousand factors besides nutrition on which one could base one’s dietary choices: taste, convenience, culture, ethics...
Personally I think the Taubes/paleo picture is probably more right than the conventional picture (based mainly on the smart people I know who have studied the issue), but I’m far from convinced that optimizing my diet for paleo-nutrition would produce a net benefit for my life. (I suppose I could explain what evidence would convince me if anyone cared.)
Also you haven’t mentioned the idea that when you eat could matter as much as what you eat. Thoughts on intermittent fasting (IF)?
I think IF is great.
I’m currently abroad and can’t stick to my normal insanely spartan diet. About once a week I start to feel a little off: knotted stomach, lethargy, etc. I do a short fast, usually only 20 hours or so, and go for a long walk, and by the end I’m feeling sharp and ready to eat subpar food once again!
When I’m home in the States I eat an insanely strict diet. When I fast I don’t notice any improvement in mood or health. I still IF from time to time though, just because there seems to be some evidence it might be healthy, and because, hell, sometimes it’s nice to not have to cook myself three meals every day.
I suspect that you are seriously overstating the difference between the status quo position and Taubes position. Taubes may be guilty of the same overstatement (positioning an argument as boldly contrarian probably helps attract attention and sell books).
I don’t think there is anyone who disagrees with the statement that “too much fat is bad for us”. Does Taubes really think that eating any amount of fat is acceptable? I assume Taubes would frown on a 100% fat diet. It seems that Taubes would agree with the government that “too much fat is bad”.
You seem to be implying that this statement is anti-dietary fat, when in fact, it is discouraging having high levels of bodyfat, which Taubes seems to agree with, since he blames obesity (implying obesity is bad) on high carb diets.
From the New York Times article:
Either Taubes is throwing out a straw man here, or his opponents are ridiculously simplistic. It’s pretty well established that some fat can be good for you, and length of life is based on a whole ton of factors.
The problem with nutritional science is that you don’t need any sort of expertise to get a platform, you just need strong opinions. See both Taubes and his opponents. Those kinds are always trying to scare you into buying their latest book by simplistically dividing food into “good” and “bad” types, and insisting you’ll die if you keep eating the bad ones. Not to mention lose weight if you eat the good ones.
Weight management boils down to simple physics, namely the First Law of thermodynamics. If you consume less energy while spending more (via exercise mainly), you’ll lose weight. One calorie is completely interchangeable with another calorie, it doesn’t matter where it came from. (The exception being that it’s easier to add muscle mass by eating proteins.)
The hard part about losing weight isn’t knowing what to eat, it’s having the willpower to eat less (or exercise more). Of course, you can’t sell a book by telling everyone “we’re fat because we have no willpower”. “We’re fat because we’ve been lied to”, however, will sell.
(EDIT: I’m going to add some clarifications on my position here because the feedback shows that I’ve made my position seem more extreme than I intended.
First, I shouldn’t have said it was simple, it’s not.
If you eat just until you’re full and you get moderate exercise but you’re still overweight, you should talk to your doctor. You may still need to change your eating or exercising habits, but you should do research first, and not make any sweeping changes all at once. And you should never have to be constantly hungry, or end up having to eat almost nothing. Both outcomes are extremely unhealthy.
Changing your habits is always difficult, and that’s where the willpower comes in. It should only be needed until you settle into your new habits, though.
I’m not trying to compare the metabolisms of separate people. Some people can eat a lot more than others and maintain a healthy weight.
I’m not trying to say you can cut food willy-nilly and still be healthy. I’m not trying to use energy balance as a curiosity stopper. I’m trying to use it to combat claims that you can eat as much “good” food as you want as long as you avoid “bad” food.)
I disagree that weight management boils down to simple physics. An active fat person can expend more energy and take in less calories than a thin person that eats a lot. And the fat one will not lose weight—the thin one will not gain.
Willpower is not the answer. You hold your breath, use your willpower to keep from breathing and in a few minutes you will lose your willpower. Use your willpower to not drink any liquid. After a couple of days your willpower will disappear and you will have a drink. Use your willpower not to eat and in a few weeks your willpower will get weak. It is a trap for the fat. They are told to use their willpower to lose weight and for a few months it may work but soon you have to eat even less to keep losing. You end up eating practically nothing. Eventually you are not fat and you eat like everyone else. The weight comes back with interest and you would have been better off if you hadn’t dieted. It is possible to lose weight but not if the only thing you can bring to it is willpower. You also need some information about what to eat and how to exercise and how slowly to take it.
I do agree with you about the money make in the nutrition/diet business.
Thanks for pointing out something else I should have clarified in my first post.
I’m not trying to compare the metabolisms of multiple people. Some people can eat a lot more than others and maintain a healthy weight.
All I’m saying is that if a single person wants to lose weight, and they reduce their caloric intake (or increase caloric expenditure) while keeping everything else the same as they were doing before, they will lose weight. And I agree that if the person returns to old habits, they will gradually return to their original weight.
You’re right in that I overstated the willpower angle. Possibly the best diet is one that’s easy to adhere to, thus reducing the necessary willpower expenditure. I wonder if that’s the real reason there’s so many different diets out there; some people find it easier to reduce carbohydrates, others fats. Which diet works best may depend on individual food preference more than biochemistry.
Caloric expenditure is not strictly a function of behavior. Holding all else constant, including amount of exercise, reducing caloric intake will also reduce expenditure. Sometimes it will reduce it by more than the reduction in intake. Sometimes it will cause the body to fail to maintain muscles properly, in which case the reduction in expenditure will persist even after returning to old habits.
The energy-balance story is not literally false, but it is so oversimplified that it’s useless; and worse, it acts as a curiosity stopper. If you are repeating it because you believe that hearing it more times will help people improve their health, then please stop, because it won’t.
I know, this is why when people stop dieting and return to their original level of consumption, they sometimes end up heavier than before, as Janet mentioned. It’s usually better to increase exercise rather than decrease calorie intake, but this thread is about diet, so I haven’t really gone into that.
Not to say it can’t, but I’ve never heard of this happening. Reference, please?
Once again, it seems I’ve stated my position badly. I really shouldn’t have used the word “simple” in my opening post. Nothing in biology is simple.
I’m not trying to say you can cut food willy-nilly and still be healthy. I’m not trying to use energy balance as a curiosity stopper. I’m trying to use it to combat claims that you can eat as much “good” food as you want as long as you avoid “bad” food.
Hang on—does “as much ‘good’ food as you want” mean “arbitrarily much food”, or does it mean “enough to sate appetite and no more”? My position is that the latter ought to be okay, and if it isn’t, it’s because something is wrong that needs to be dealt with directly, using thought and observation, not willpower.
I was using it to mean “arbitrarily much food”. My position is similar: If you eat just until you’re full and you get moderate exercise but you’re still overweight, you should talk to your doctor. You may still need to change your eating or exercising habits, but you should do research first, and not make any sweeping changes all at once.
Changing your habits is always difficult, and that’s where the willpower comes in. It should only be needed until you settle into your new habits, though. And you should never have to be constantly hungry, or end up having to eat almost nothing, as Janet said. Both outcomes are extremely unhealthy.
I think I’ll add this to my original post to clarify my position. I seem to have come across as more extreme than I intended.
The last I heard, losing weight tends to increase appetite, not lower metabolism.
Starving yourself does reduce calories burned due to spontaneous fidgety behavior (are you really relaxed and holding still while you’re at the computer?), as well as metabolic processes (even on a bodyweight-relative basis), by which I mean whatever energy is expended outside gross motion.
However, most people using this phenomena as an excuse are conveniently overestimating its magnitude (and/or underestimating their caloric intake). This helps them combat the stigma of moral weakness (often wrongly) associated with being fat.
I was talking about theories that starvation lowers basal metabolism, even after food is more available.
No, this is wrong. If you have to use willpower to suppress your appetite, then either one of your appetite-regulation mechanisms is malfunctioning, or your appetite-regulation mechanisms are working correctly but you’re deficient in a vital nutrient. Telling people to use willpower to eat less is harmful in both cases—in the former case, because it stops them for looking for the real cause of their overeating (usually sugar), and in the latter case by making them starve themselves (usually of protein).
I agree with everything you said until you mentioned that sugar is the real cause of people overeating. There are a lot of possible reasons for someone to overeat, and none of them, in my opinion, are solely dietary. The cause may be psychological—for example, a lot of people eat when they’re depressed or bored. I myself sometimes succumb to the latter. Some people hate to exercise. Willpower will help in all of those cases.
The only case I can think of where sugar might be considered the culprit is if someone drinks way too many sodas, for example. But the problem isn’t the fact that it’s sugar in the soda, it’s that the person is consuming a lot of extra calories they wouldn’t otherwise get. They’d be just as overweight as if they ate a calorically equivalent amount of potato chips. They need the willpower to stop their soda habit.
Regarding nutrient deficiencies, I’ve only been talking about calories, not other types of nutrients. I apologize for not making this clear in my first post. Obviously, if you need more vitamin C, you’re better off drinking some orange juice than a calorically equivalent amount of soda. You should always have a varied diet that contains enough essential vitamins, minerals, and amino acids.
The bit about sugar being a cause for misregulation of appetite was a parenthetical remark, which the rest of the comment does not depend on. That said, I think you’re drastically underestimating the amount of harm sugar does. Blood sugar is one of the main mechanisms for regulating appetite, and drinking soda completely destroys its functionality.
Regarding nutrient deficiencies, I wasn’t just talking about micronutrients like vitamin C, but also to macronutrients. For example, if someone’s problem is that they aren’t eating any fat, then no amount of low-fat food will ever suffice to make them feel full.
It’s definitely true that some amount of dietary fat and protein should be considered nearly essential (but a typical fast food diet will far exceed all those minimums). I think the same is also true of carbs but almost nobody fails to get enough sugar.
If this is the case, what mechanism explains the steady decline in willpower over the last 70 years?
What steady decline?
Over the past 70 years, obesity has increased significantly, as have heart disease and several other related diseases. If someone wants to argue that obesity is caused by low willpower (as the above poster at least partially claims)
then I want to see some explanation for why willpower has declined over that time period. If someone tells me diet changes have caused obesity and they point to diet changes over the past N years and rising obesity over the past N years, the pieces of their story fit together. So I’m asking (somewhat skeptically) what’s the mechanism for the willpower story? How does it fit the observed trend?