Long-time subscribers to this list will be all-too-familiar with my continuing dissing of the traditional cut-offs for overweight and obesity. My contention (stop rolling your eyes!) is that claims of an epidemic of obesity are enhanced by using cut-offs which are too low for the real relation of body mass index (BMI) to mortality.
Here's a new study which supports that contention, at least for men. It's: Gronniger, J. (2006). A semiparametric analysis of the relationship of body mass index to mortality. American Journal of Public Health, 96, 173-178. I don't have a clue about semiparametric analysis, and I don't yet have the paper. But according to the abstract, "normal" weight men (BMI 20-25), are just as likely to buy the farm as men conventionally classified as obese (BMI 30-35). Really! Minimum risk is at a BMI of 26, which is conventionally classed as overweight. For women, lowest risk was within the normal range (at 23-24 BMI) but the risk began to rise steadily only above 27. Gronniger also says "In each specification, the slope of the line was small and volatile through the BMI range of 20-35, suggesting negligible risk differences with minor differences in weight for much of the population". He concludes "Traditional BMI categories do not conform well to the complexities of the BMI-mortality relationship. In concurrence with conclusions from previous literature, I found that the current definitions of obesity and overweight are imprecise predictors of mortality risk". My translation: the cut-offs are too low, dummy! And the bottom line seems to be that it's time doctors let up a bit on scaring overweight people into dieting by telling them to slim down or die. Gronniger's with the Congressional Budget Office, Washington, D.C. I wonder whether he's going to get in trouble for saying that. There are some things left unsaid in the abstract. I'd like to see what the results look like for non-smokers, because smokers have other more important things to worry about than obesity. And the data may look different as a function of race. I recall that in one study, Black women didn't show an increase in mortality with even very high values of BMI. Stephen ----------------------------------------------------------------- Stephen L. Black, Ph.D. Department of Psychology Bishop's University e-mail: [EMAIL PROTECTED] Lennoxville, QC J1M 1Z7 Canada Dept web page at http://www.ubishops.ca/ccc/div/soc/psy TIPS discussion list for psychology teachers at http://faculty.frostburg.edu/psyc/southerly/tips/index.htm ---------------------------------------------------------------------- - --- You are currently subscribed to tips as: [email protected] To unsubscribe send a blank email to [EMAIL PROTECTED]
