We, as a culture, have some weird views about appetites. We accept readily that some people are just born with an appetite for alcohol and drugs while others aren’t. We accept that the former would have to struggle much more to control their drinking (say) than the latter for their entire lives. If people vary in their sexual appetites, we tend to think those on the lower end of the desire scale are probably just repressed in some way. And what about eating? Easy. Thin people eat less and exercise more. Fat people eat more and exercise less. It’s simple thermodynamics. Ask fat people to exercise more and eat less – and boom, obesity problem solved. The ones who don’t do that – well, they’re just out of control. They eat even when they are not hungry. They are self-indulgent.
So the advice – eat less, move more! – is given over and over and over again, by medical professionals and Oprah and the First Lady. The statistics, however, are grim. Less than 5% of people who lose weight by any method keep it off for ten years. Those stats are worse than heroin addiction.
I cannot imagine the medical community recommending a medication that had a less than 5% long term success rate and came with plenty of unpleasant side effects, such as irritability, constant hunger, severely restricted ability to socialize. Yet the advice remains: eat less, move more!
If it is that simple, why doesn’t the advice work?
I used to believe the “simple thermodynamics” idea, and I used to be fat. Then I started a medication for another condition, and my desire to eat shifted drastically. All of a sudden, I didn’t crave eating nearly so much, and I lost weight without nearly as much effort as I used to use. And the thing is, we all know this. Everyone knows that certain drugs, such as amphetamines or pot, can affect appetite. Yet we still have this odd persistence of belief that people are equally in control of their appetites, and the ones who are fat are just more weak-willed than the rest of us. On becoming thinner, I became privy to the contempt in which thin people hold fat people. It is intense.
There is a cultural explanation of obesity as well. Food deserts, advertising, etc. The question remains. Why are some people particularly susceptible to such messages? Two people can live in the same environment, and one will get fat and another won’t.
We seem weirdly resistant to the idea that weight gain can depend on an individual, yet not be an individual’s fault. Yet we at least partially accept this in the case of, say, alcoholism.
If Gary Taubes has done nothing else, he has done an excellent job in tracing the origins of our belief in the thermodynamics explanation of weight. If you are truly interested, I highly recommend his book Good Calories, Bad Calories. Even if you don’t accept his positive hypothesis, that is, that the obesity epidemic is caused by wide availability of sugar and carbs, his take-down of the eat-less-move-more advice is thorough, convincing, and valuable.
For those who don’t have the time to wade through his book, here’s a nice link on the philosophical problem of the thermodynamic explanation – that is, that the thermodynamics of weight gain are trivially true.
Say instead of talking about why fat tissue accumulates too much energy, we want to know why a particular restaurant gets so crowded…. So what we want to know is why this restaurant is crowded and so over-stuffed with energy (i.e., people) and maybe why some other restaurant down the block has remained relatively empty — lean.
If you asked me this question — why did this restaurant get crowded? — and I said, well, the restaurant got crowded (it got overstuffed with energy) because more people entered the restaurant than left it, you’d probably think I was being a wise guy or an idiot. (If I worked for the World Health Organization, I’d tell you that “the fundamental cause of the crowded restaurant is an energy imbalance between people entering on one hand, and people exiting on the other hand.”) Of course, more people entered than left, you’d say. That’s obvious. But why?And, in fact, saying that a restaurant gets crowded because more people are entering than leaving it is redundant –saying the same thing in two different ways – and so meaningless.
Now, borrowing the logic of the conventional wisdom of obesity, I want to clarify this point. So I say, listen, those restaurants that have more people enter them then leave them will become more crowded. There’s no getting around the laws of thermodynamics. You’d still say, yes, but so what? Or at least I hope you would, because I still haven’t given you any causal information. I’m just repeating the obvious.
This is what happens when the laws of physics (thermodynamics) are used to defend the belief that overeating makes us fat. Thermodynamics tells us that if we get fatter and heavier, more energy enters our body than leaves it. Overeating means we’re consuming more energy than we’re expending. It’s saying the same thing in a different way…
Answering the “why” question speaks to actual causes. In the restaurant analogy, okay, maybe this restaurant has particularly great food, or it’s happy hour; the drinks are cheap. Maybe it’s pouring outside so a lot of people ran into the restaurant to stay dry. Maybe every other restaurant in the neighborhood, including our lean restaurant down the block, was recently closed by the local health bureau and this is the only one that didn’t have cockroaches in the kitchen and so remained open. Maybe it’s in the theater district and the shows just got out and now every restaurant in the neighborhood is packed with the post-theater crowd. Maybe the word has spread that Brad Pitt and Angelina Jolie frequent this restaurant regularly, or Oprah, and this attracted a crowd hoping for a glimpse of celebrity.
All these would be valid answers to the question we asked. Some speak to the conditions inside the restaurant (the quality of the food, the price of the drinks, celebrity customers); some speak to conditions immediately outside (a rain storm, no competition, the theater schedule). They all provide the causal information we’re seeking. They answer the “why” question. That more people are entering than leaving doesn’t. It’s what logicians call “vacuously” true. It’s true, but meaningless. It tells us nothing. And the same is true of overeating as an explanation for why we get fat. If we got fat, we had to overeat. That’s always true; it’s obvious, and it tells us nothing about why we got fat, or why one person got fat and another didn’t…
As for the great majority of experts who say (and apparently believe) that we get fat because we overeat or we get fat as a result of overeating, they’re the ones making the junior-high-school-science-class mistake: they’re taking a law of nature that says absolutely nothing about why we get fat and assuming it says all that needs to be said. This was a common error in the first half of the 20th century. It’s become ubiquitous since.
Here’s another bit he wrote recently on the new HBO documentary on obesity which sums up his view nicely, and here’s a criticism of him which echoes my own hesitance about him, i.e., I totally buy his critical view, and am not 100% sold on his positive view. That said, I lose weight eating low carb. The more fat I eat, the more weight I lose. It is also a kind of unpleasant way to eat, and not in line with my ethics. I’d like it not to be true. I am ethically sympathetic to vegetarianism. When I tried to follow through on that recently, I gained weight and became anemic. So I am now restricting myself to well-treated animals as an ethical second-best.
Yet if his criticisms can get at least some people to stop giving fat people the simple eat-less-move-more, and stop the contempt for them, Gary Taubes has done amazing work.