With health care in the news, everyone's looking for magic bullets to save money. Obesity seems to be a growing favorite: wouldn't it be great if we could make everyone look like Jennifer Anniston, and be cheaper to treat? There are a lot of holes in this theory--the morbidly obese are very sick, but die young, while lower levels of overweight/obesity aren't so well correlated with poor health. But still, the idea's power seems to be growing every day.
This week, Health Affairs published a new study showing that--quel surprise!--obesity accounts for an ever growing share of our health care costs. They put the number at about 10%. So I decided to ask Paul Campos, the author of The Obesity Myth, what he thought. The book, which everyone should read, argues that the health benefits of losing weight are largely imaginary; that we are using "health" to advance our class bias in favor of thin people, particularly thin women.
Megan: The CDC is sponsoring a conference on obesity this week. In conjunction with this, the journal "Health Affairs" just published a study showing that almost 10% of US medical costs may be due to obesity. As we're debating the costs of a public health care plan, controlling obesity is moving even further to the forefront of the American public health agenda. What should we think of this?
Paul: It's a terrible idea on all sorts of levels. There are three big problems with attempting to control health care costs by reducing so-called "obesity." First, it's a fake problem. Second, the solutions for the problem are non-existent, even assuming the problem existed. Third, focusing on making Americans thinner diverts resources from real public health issues.
Megan: Let's start with the first. If there's one thing that everyone in America knows, it's that being fat is really unhealthy. Why do you call it a fake problem?
Paul: The correlations between higher weight and greater health risk are weak except at statistical extremes. The extent to which those correlations are causal is poorly established. There is literally not a shred of evidence that turning fat people into thin people improves their health. And the reason there's no evidence is that there's no way to do it.
So saying "let's improve health by turning fat people into thin people" is every bit as irrational as saying "let's improve health by turning men into women or old people into young people". Actually it's a lot crazier, because there actually are significant health differences between men and women and the old and the young -- much more so than between the fat and the thin.
Megan: So why is the public health community so set on this issue as the major driver of our health care costs?
Paul: Because we're in the midst of a moral panic over fat, which has transformed the heavier than average into folk devils, to whom all sorts of social ills are ascribed.
Megan: Aside from rising health care costs?
Paul: Well according to the obesity mafia our kids are all going to die sooner than their parents, which sounds like a moral problem as well as one of health care costs. It's all complete nonsense.
Megan: Do you think being overweight is a proxy for things that DO make a difference, like fitness?
Paul: It's a weak proxy, but yes it has some marginal significance. It's good to encourage people of all sizes to be active and avoiding eating disordered behavior (like dieting), but this isn't because lifestyle changes will make fat people thin people. They won't. I'd like to talk a little about the statistics if I may. : Please! We're all about statistics here.
Paul: OK, the CDC honchos and the authors of this study you referenced are in hysterics because the obesity rate, so-called, has roughly doubled in the last 30 years. But let's consider what that actually means.
Obesity is defined completely arbitrarily as a body mass index of 30 or higher (175 pounds for an average height woman). Now body mass follows more or less a normal distribution, whiich means if the the mean body weight is in the mid to high 20s, which it has been for many decades now, then tens of millions of people will have BMIs just below and just above the magic 30 line. So if the average weight of the population goes up by ten pounds, tens of millions of people who were just under the line will now be just over it.
This might be meaningful if there was any evidence that people who have BMIs in the low 30s have different average health than people with BMIs in the high 20s, but they don't. At all. So the "obesity epidemic" is 100% a product of tens of millions of people having their BMIs creep over an arbitrary line. It's exactly as sensible as declaring that people who are 5'11 are healthy but people who are 6'1" are sick.
Adding to the absurdity of all this, people with BMIs in the mid to high 20s actually have the best overall health and longest life expectancy -- ,more so than those in the so-called "normal" BMI range.
Megan: So we can't save billions of dollars by making people thinner?
Paul: Consider the methodology of this study. It tried to calculate changes in health costs if everybody with a BMI over 30 had a BMI under 25. But leaving aside the preposterous assumption that all increased health risks associated with a level of body mass are caused by that level of body mass, the idea that somehow we could make fat people into thin people is bizarre.