Related To: The Unfinished Mystery of the Shangri-La Diet and Missed Distinctions
Megan McArdles blogs an interview with Paul Campos, author of The Obesity Myth. I'll let anyone who is interest read the whole thing, but here's some interesting excerpts:
I mean, there's no better established empirical proposition in medical science that we don't know how to make people thinner. But apparently this proposition is too disturbing to consider, even though it's about as well established as that cigarettes cause lung cancer. So all these proposals about improving public health by making people thinner are completely crazy. They are as non-sensical as anything being proposed by public officials in our culture right now, which is saying something.
It's conceivable that through some massive policy interventions you might be able to reduce the population's average BMI from 27 to 25 or something like that. But what would be the point? There aren't any health differences to speak of for people between BMIs of about 20 and 35, so undertaking the public health equivalent of the Apollo program to reduce the populace's average BMI by a unit or two (and again I will emphasize that we don't actually know if we could do even that) is an incredible waste of public health resources
and
Megan: An economist recently pointed out that we don't encourage people to move to the country, even though rural people live more than three years longer than urban people, and the diffefence in their healthy life expectancy is even more outsized. Nor do we encourage people to find Jesus or get married. We target "unhealthy" behaviors that are already stigmatized.
Paul: Right, as Mary Douglas the anthropologist has pointed out, we focus on risks not on the basis of "rational" cost-benefit analysis, but because of the symbolic work focusing on those risks does -- most particularly signalling disapproval of certain groups and behaviors. In this culture fatness is a metaphor for poverty, lack of self-control, and other stuff that freaks out the new Puritans all across the ideological spectrum, which is why the war on fat is so ferocious -- it appeals very strongly to both the right and the left, for related if different reasons.
The amount of irrationality surrounding the obesity topic is really absurd. This following is a good example:
http://www.jhsph.edu/publichealthnews/press_releases/2008/wang_obesity_projections
The article claims that by 2030 86% of Americans will be overweight. This is based purely on extrapolating the trends of the last 30 years. My own reading of the actual literature on the topic implies that a large minority of people are simply not weight-gainers. They have a lower appetite or have faster metabolisms or something other factor that protects them from weight gain. My understanding is that the rate of overweight has been increasing more slowly in recent years, as essentially all the people capable of becoming overweight already have.
Also, if obesity lowers life expectancy and causes serious health problems, I would expect people who are genetically more prone to obesity to have fewer descendants. I also suspect slimmer people probably reproduce more because 1. fitter men are more sexually successful and 2. pregnancy can be complicated by obesity. Since cheap, readily available fatty foods have only been available recently, the obese-prone have never been strongly selected against until now. Basically, fast food is kicking obese people out of the gene pool.