Fighting Obesity
Policy Prof
Mark Kleiman has an interesting post discussing policy responses to the obesity epidemic, motivated by the debate over a new report that merely being
overweight doesn't increase mortality (although being obese does).
Kleiman basically suggests that we should change land-use patterns (building more walkable neighborhoods) and regulate convenience foods in some way. Although these measures seem commonsensical, and maybe they're worthwhile things to do, I think they're largely beside the point.
Kleiman's common sense proposals go both too far and not far enough. They go too far because they're very broad-based interventions affecting everybody, when the real problem is relatively concentrated. Obesity mainly kills people with BMIs of 35 or more, about 13% of the population. In other words, for a 5'8" person, obesity starts to have serious consequences when you're around 65 pounds or more overweight.(*)
They don't go far enough because they don't do that much. Personally, I doubt that making more walkable cities will do anything at all (that's a subject for another post, but see Cutler et al for a
convincing argument on this point). But even if better land use planning does help, it's not going to help anytime soon. It's a project for decades. What kind of response is that to a problem that's killing 100,000 or more per year?
I'd guess that regulating fast food and such is more likely to be helpful (again, see Cutler et al), but is this really likely to happen? I can imagine the government cracking down on candy and soda in schools, but not much else. Are there really any junk food regulations that have any chance of gaining political support?
Finally, even if commuting by car and the availability of junk food are what's making Americans so fat, that reversing these trends will make us thin. Once you gain weight, it's very hard to lose it: your body adapts a new set point, and fights to keep you at your new weight. So, these proposals might help the next generation, but not necessarily help people who are already overweight.
So, what' s a better response? First more research, into things like appetite control drugs, and breast feeding. Yes,
breast feeding. It looks pretty likely that
influences in the womb and the first months of life have a large effect on obesity later in life.
Also, there's really only one thing that' s been proven to result in significant weight loss, and it's not dieting, excerise, or drugs. It's
gastric bypass surgery ("stomach-stapling"), which about
140,000 people have every year, in spite of the dangers. You want a policy proposal? How about insisting that
Medicaid and private insurance cover this procedure?
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(*) The
Flegal et al study discussed in the Times reports that there are about 30,000 extra deaths per year among the obese (BMI 30-35) and 82,000 among the extremely obese (BMI 35+), so lower levels of obesity aren't necessarily risk-free. Or maybe they are safe: the study looks at several decades of data, and BMIs of 30-35 increase mortality only in the 1970s, not the 1980s or 1990s. But in any event, I think it's fair to say that obesity is only a serious health problem for about 13% of the population.
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