Weight and Mortality IV: this changes everything
Having reviewed the JAMA study itself, considered the question of what might account for increased mortality in the thin, and criticized BMI as a measurement of obesity and the arbitrary categories used to pigeonhole people, I now want to consider the implications of the study for public health.
Basically, it boils down to me being extremely healthy. I eat an okay diet (too much junk, but lots of good stuff, too), exerciese pretty regularly, have good cholesterol numbers and drink alcohol in moderation. My blood pressure is normal. Until now I'd have said I'd be really healthy if i could just lose 10 or 15 lbs and keep it off. Turns out I'm fine where I am (BMI 27 or so).
My mom is pretty thin and my dad has always struggled with his weight. Until now. Now my dad is in good shape and my mom needs to put on a few lbs, especially as they head up in years. Well, maybe not. The study showed an association not causality, which is always an issue in epidemiologic studies.
All that stuff you read about calorie restriction extending lifespan. Probably crap. Wouldn't it suck to restrict starve yourself for twenty years and then figure out you had SHORTENED your life? But since the thin (and BMI<18.5 is really thin) die younger, it is hard to imagine drastically reducing calories would decrease mortality.
And how would you feel if you'd just published an article in the New England Journal of Medicine arguing that increases in life expectancy were threatened by increasing obesity (my criticism is here)? Pretty foolish, huh? Maybe life expectancy would increase if we could get thin folks to eat some more
Most of all I think this means people can relax. Eat an okay diet, get some exercise, have a glass of wine or beer a couple times a week (or day) and don't worry so much about your weight.
It seems every week we read about some public health initiative designed to decrease obesity in one group or another. But maybe that's the wrong focus. Probably we should focus on encouraging healthy behaviors rather than the Sisiphyean task of encourage weight loss.