Since there seems to be some interest in it, I’d like to clarify a few things about what exactly my position is on various weight and health-related matters.
(1) Obesity does correlate with some increased health risks, and to a largely unknown extent, has a causal role in some of those increased risks. However:
(a) The extent of the correlations is greatly exaggerated.
(b) The extent to which the correlations are causal is also greatly exaggerated, since the baseline assumption tends to be that correlation simply equals causation in this context.
(c) Obesity does not appear to even correlate with increased mortality risk until weight levels that are higher than those of most people in America defined as obese.
(2) Overweight (BMI 25-29.9) does not correlate with increased overall health risk in any meaningful way, and correlates with lower mortality risk than so-called “normal” weight. Most people who are categorized as weighing too much by public health authorities are in the overweight category.
(3) Obesity also correlates with decreased health risk in certain contexts. For example, among people who have cardiovascular disease (the single biggest cause of death in America) “obese” people have better survival rates than non-obese people. This is the so-called “obesity paradox,” which is only a paradox if you take it as axiomatic that obesity is unambiguously a bad thing from a health perspective.
(4) Individual attempts to achieve significant long-term weight loss fail in the the overwhelming majority of cases. Public health interventions designed to produce weight loss fail uniformly. Dieting doesn’t work; furthermore the difference between “dieting” and eating disordered behavior is merely one of degree. Eating disorders are common consequences of dieting.
(5) It is not known if significant long-term weight loss is beneficial to health. Attempts to answer this question have been stymied by (4).
(6) Being moderately physically active appears to eliminate most or all of what increased health risk is observed among “obese” people.
(7) The Health at Every Size movement advocates healthy lifestyles for people of all sizes, including children of all sizes. I strongly support such advocacy. Examples of the HAES approach to these issues, broadly speaking, can be found here, here, here, and here, among many other places.
(8) The official government definition of a a “normal healthy weight” of BMI 18.5 to 24.9, besides being without any scientific foundation, is inherently stigmatizing to people who are not “normal” or “healthy” in these misused senses of the words normal and healthy. (This BMI range isn’t statistically normal, nor does it correlate with the lowest health risk). Stigmatization is, among other things, bad for peoples’ health.
(9) This issue is strongly gendered. Weight oppression is, among other things, a form of sexism, as body surveillance is far more intense toward the bodies of women and girls than toward those of men and boys.
(10) Telling fat people, and especially fat children, that it’s bad to be fat, and that they wouldn’t be fat if they had healthy lifestyles, is both false and destructive.