Previously: Mainstream Nutrition Science on Obesity, Atkins Redux

Here's where I start talking about the thing that initially drove me to write this post series: Taubes' repeated misrepresentation of the views of the mainstream nutrition authorities he attacks. I'll start by going back to Taubes' 2002 article. Immediately after the discussion of Atkins, it contains another set of claims that stood out to me as a huge red flag: 

Thirty years later, America has become weirdly polarized on the subject of weight. On the one hand, we've been told with almost religious certainty by everyone from the surgeon general on down, and we have come to believe with almost religious certainty, that obesity is caused by the excessive consumption of fat, and that if we eat less fat we will lose weight and live longer. On the other, we have the ever-resilient message of Atkins and decades' worth of best-selling diet books, including ''The Zone,'' ''Sugar Busters'' and ''Protein Power'' to name a few. All push some variation of what scientists would call the alternative hypothesis: it's not the fat that makes us fat, but the carbohydrates, and if we eat less carbohydrates we will lose weight and live longer.

The perversity of this alternative hypothesis is that it identifies the cause of obesity as precisely those refined carbohydrates at the base of the famous Food Guide Pyramid -- the pasta, rice and bread -- that we are told should be the staple of our healthy low-fat diet, and then on the sugar or corn syrup in the soft drinks, fruit juices and sports drinks that we have taken to consuming in quantity if for no other reason than that they are fat free and so appear intrinsically healthy. While the low-fat-is-good-health dogma represents reality as we have come to know it, and the government has spent hundreds of millions of dollars in research trying to prove its worth, the low-carbohydrate message has been relegated to the realm of unscientific fantasy.

I'll start with the obvious: We thought sugary soft drinks were intrinsically healthy? To quote an old joke, who do you mean we, kemosabe? Given widespread scientific illiteracy, I wouldn't be surprised if some people have believed that low-fat is a sufficient condition for being healthy, but if so, they didn't get this idea from mainstream nutrition science.

Related: Trusting Expert Consensus

Lately, I've been thinking a lot about whether we can find any clear exceptions to the general "trust the experts (when they agree)" heuristic. One example that keeps coming up—at least on LessWrong and related blogs—is Gary Taubes' claims about mainstream nutrition experts allegedly getting obesity horribly wrong.

Taubes is probably best-known for his book Good Calories, Bad Calories. I'd previously had a mildly negative impression of him from discussion of him on Yvain's old blog, particularly some of other posts Yvain and other people linked from there, such as this discussion of Taubes' "carbohydrate hypothesis" and especially this discussion of Taubes' attempt to refute the standard calories-in/calories-out model of weight.

But I figured maybe the criticism of Taubes I'd read hadn't been fair to him, so I decided to read him for myself... and holy crap, Taubes turned out to be far worse than I expected. I decided to write a post explaining why, and then realized that, even if I were somewhat selective about the issues I focused on, I had enough material for a whole series of posts, which I'll be posting over the course of the next week.

The problem with Taubes is not that everything he says is wrong. Much of it is ludicrously wrong, but that's only one half of the problem. The other half is that he says a fair number of things mainstream nutrition science would agree with, but then hides this fact, and instead pretends those things are a refutation of mainstream nutrition science. So it's worth starting with a brief in-a-nutshell version of what mainstream nutrition science actually says about obesity.

(The following summary is drawn from a number of sources, including this, this, and this. Everything I'm about to say will be discussed in much greater detail in subsequent posts.)

Here it goes: people gain weight when they consume more calories than they burn. But both calorie intake and calorie expenditure are regulated by complicated mechanisms we don't fully understand yet. This means the causes of overweight and obesity* are also complicated and not fully understood. It is, however, worth watching out for foods with lots of added fat and sugar, if only because they're an easy way to consume way too many calories.

We currently don't have any great solutions to the problem of overweight and obesity. If you consume fewer calories than you burn, you will lose weight, but sticking to a diet is hard. It's relatively easy to lose weight in the short run, and it's possible to do so on a wide variety of diets, but only a small percentage of people keep the weight off over the long run.

As for low-carb diets, people do lose weight on them, but they do so because low-carb diets generally lead people to restrict their calorie intake even when they aren't actively counting calories. For one thing, it's hard to consume as many calories when you drastically restrict the range of foods you can eat. There's also some evidence that low-carb diets may have some advantages. in terms of, say, warding off hunger, but the evidence is mixed. There's certainly no basis for claiming low-carb diets as a magic bullet for the problems of overweight and obesity.

The above points are not the only issues at stake in Taubes' writings on nutrition. Admittedly, he covers a huge amount of ground, from the relationship between sugar and diabetes to the relationship between fat intake and heart disease to the alleged dangers of extremely-low carbohydrate diets. However, I'll be focusing on his claims about the causes of and solutions to the problems of overweight and obesity, because that seems to be the main thing people talk about when they talk about Taubes supposedly showing how wrong mainstream experts can be.

I'll also focus heavily on how Taubes misrepresents the views of mainstream experts on obesity. In the next post, though, I'll be temporarily setting that issue aside in order to look at what Taubes is proposing as an alternative. This will involve examining some claims made by Dr. Robert Atkins, whose ideas' Taubes champions.

*Note: if the use of "overweight" as a noun sounds weird to you, it does to me too, but I discovered as I researched this article that it's standard usage in the literature on the subject. I came to realize there's a good reason for this usage: it's inaccurate to talk about the problem solely in terms of "obesity," but constantly saying "the problem of people being overweight and obese" gets really wordy.

Next: Atkins Redux

Previously: Mainstream Nutrition Science on Obesity

Edit: In retrospect, I think it maybe should have combined this post with part 3. Unfortunately, the problem of what to do with existing comments makes that hard to fix now.

Taubes first made a name for himself as a low-carb advocate in 2002 with a New York Times article titled "What if It's All Been a Big Fat Lie?" When I first read this article, I was getting extremely suspicious by the second paragraph (emphasis added):

If the members of the American medical establishment were to have a collective find-yourself-standing-naked-in-Times-Square-type nightmare, this might be it. They spend 30 years ridiculing Robert Atkins, author of the phenomenally-best-selling ''Dr. Atkins' Diet Revolution'' and ''Dr. Atkins' New Diet Revolution,'' accusing the Manhattan doctor of quackery and fraud, only to discover that the unrepentant Atkins was right all along. Or maybe it's this: they find that their very own dietary recommendations -- eat less fat and more carbohydrates -- are the cause of the rampaging epidemic of obesity in America. Or, just possibly this: they find out both of the above are true.

When Atkins first published his ''Diet Revolution'' in 1972, Americans were just coming to terms with the proposition that fat -- particularly the saturated fat of meat and dairy products -- was the primary nutritional evil in the American diet. Atkins managed to sell millions of copies of a book promising that we would lose weight eating steak, eggs and butter to our heart's desire, because it was the carbohydrates, the pasta, rice, bagels and sugar, that caused obesity and even heart disease. Fat, he said, was harmless.

Atkins allowed his readers to eat ''truly luxurious foods without limit,'' as he put it, ''lobster with butter sauce, steak with béarnaise sauce . . . bacon cheeseburgers,'' but allowed no starches or refined carbohydrates, which means no sugars or anything made from flour. Atkins banned even fruit juices, and permitted only a modicum of vegetables, although the latter were negotiable as the diet progressed.

It's one thing to claim that, all else equal, low-carb diets have advantages over low-fat diets. It's another thing to claim you can eat unlimited amounts of fatty foods without gaining weight.

My mother won't watch animated movies.  It doesn't matter what the content is.  Whether it's Sponge Bob or Grave of the Fireflies, she believes that animation is used only for shows for children, and that adults shouldn't watch shows for children.  She's incapable of changing this belief, because even if I somehow convince her to sit and watch an animated film, she sees what she expects, not what's in front of her.

I think this is the same thing that creation scientists and climate-change deniers do.  They literally cannot perceive what is in front of them, because they are already convinced they know what it is.

Here's an interesting test, which I discovered by accident:  There's a hilarious series of fan-made parodies of My Little Pony: Friendship is Magic on YouTube called Friendship is Witchcraft.  They took show videos and redubbed them to have different stories in which various ponies are robots, fascists, or cult members planning to awaken Cthulhu.  I've shown these videos to four people without explanation, just saying "You've got to see this!" and bringing up "Cute From the Hip" on YouTube.

The same thing always happens.  They watch with stony, I-must-be-polite-to-Phil faces, without laughing.  Eventually I realize that they think they're watching an episode of My Little Pony.  I explain that it's a parody, and they say, "Oh!"  I'd think that lines like "I know we've taught you to laugh in the face of death," "If you think one of your friends is a robot, kids, report them to the authorities so that they can be destroyed!", "I'm covered in pig's blood!", or, "Are you busy Friday?  We need a willing victim for our ritual sacrifice" would prompt some questions.  They don't.  They are so determined to see a TV show for little girls that that's what they see, regardless of what's in front of them.