Dan Goldstein sent me this link, with the note, “possibly interesting to you / Seth.”
What I’m wondering is, will Seth be happy because it shows how conventional medical research has failed, or will he be unhappy because it finds that losing weight is not such a great thing?
I don't take the study very seriously — it's correlational. Tim Beneke lost a lot of weight and his knees and blood pressure greatly improved. Not to mention his self-image. That single example I find more revealing of cause and effect in the area of weight control. When it becomes possible to do experiments where people lose lots of weight then we'll start to learn more about what's the best weight.
The previous study was discussed in a recent special issue of Scientific American on obesity. (Incidentally, I picked up the issue largely to see if they mentioned Seth — I didn't see any mention).
According to the article, Flegal's lean group included smokers and people with chronic illnesses. Supposedly when you perform a similar analysis to Flegal's while adujusting for serious illness the number of extra deaths for the obese triple.
I haven't read either of the Flegal's papers, but is seems plausible to me that the analysis is just wrong.
So Seth, you're saying that anecdotes trump data? My Aunt Ethyl has been trying to lose weight forever. Now she has learned to accept that being a few pounds overweight is not such a bad thing, and she feels much better. She may even live longer. The same is true of Uncle Fred. That's two anecdotes to your one. Do I win?
If we are going to use anecdotal "evidence", what about how our body feels? I mean, I've always feel stronger and healthier when I'm fit, then when I gain a few pounds.
Do "anecdotes trump data"? No, Beneke's case involved data. It's an experiment with n = 1, essentially. It's a case where one sort of data is more persuasive (to me, at least) than another sort of data. The new study doesn't disagree with this, in fact; it shows worse health for people with BMIs of 35 and over, which is where Beneke started. If by anecdote you mean a study where n = 1, then mosts studies are anecdotal in some way: one hospital, one city, one school, one diet.