Much of the discourse around the benefits of being thin revolves around the assumption that extra pounds are harmful to health.  Ampersand at Alas A Blog posted about a study in the New England Journal of Medicine (citation below) that shows that  those who are overweight (according to the BMI scale) are not at a higher risk of premature death than those who are deemed of “normal” weight.   The boxes in red are categories in which the risk for premature death is equal to or less than the reference group (normal weight people).

rr_by_bmi_large

This is Ampersand’s conclusion (and his table, too).

The authors of the study, as commenter A.C. pointed out,  come to the opposite conclusion.  They argue, after looking at the data in different ways, say that overweight persons are at a higher risk for death.

Ampersand doesn’t buy it.  He offers a critique here where, among other things, he points out:

In order to produce the finding that “overweight” is less healthy than “normal weight,” Dr. Adams did a very dishonest statistical manipulation – he compared just one “normal” BMI range, representing the heaviest people in the “normal” range, to the entire “overweight” range. This is because the majority of people in the “normal weight” categories had a greater risk of death than the majority of people in the “overweight” category.

This might be a great way to discuss how methods and statistics never speak for themselves.

Relatedly, this post offers a really great visual critique of the BMI scale.

Citation:  Adams, K., et al., “Overweight, Obesity, and Mortality in a Large Prospective Cohort of Persons 50 to 71 Years Old.” New England Journal of Medicine, 2006. 355(8): p. 763-8.  Here if you have a subscription to ProQuest.