Telling people being obese isn't unhealthy--not productive

[HiPointDem]

21. First, you're confusing two studies. Your first link is about an earlier study that came to similar

conclusions in 2005. Despite the critics' claims about its flaws, you can see that it addresses age & illness and that it's longitudinal -- NHANES is a survey done at regular intervals, the largest of its type for the measures it studies, so you can follow people over time -- in this case, the 70s through the 90s & the 80s through 2000. So it's immaterial that most of the deaths were of people in their 70s or older, because most weren't in their 70s when the survey began.

You'll also note that the researchers made adjustments for confounding factors & age.

We estimated relative risks of mortality associated with different levels of BMI (calculated as weight in kilograms divided by the square of height in meters) from the nationally representative National Health and Nutrition Examination Survey (NHANES) I (1971-1975) and NHANES II (1976-1980), with follow-up through 1992, and from NHANES III (1988-1994), with follow-up through 2000.

These relative risks were applied to the distribution of BMI and other covariates from NHANES 1999-2002 to estimate attributable fractions and number of excess deaths, adjusted for confounding factors and for effect modification by age.

RESULTS:

Relative to the normal weight category (BMI 18.5 to <25), obesity (BMI > or =30) was associated with 111,909 excess deaths (95% confidence interval [CI], 53,754-170,064) and underweight with 33,746 excess deaths (95% CI, 15,726-51,766). Overweight was not associated with excess mortality (-86,094 deaths; 95% CI, -161,223 to -10,966). The relative risks of mortality associated with obesity were lower in NHANES II and NHANES III than in NHANES I.

http://www.ncbi.nlm.nih.gov/pubmed/15840860?dopt=Abstract

The second link is to an article about the more recent study in the New England journal of medicine. The main criticism in this article is that the study "relies on the highly controversial Body-Mass Index (BMI) -- a simple measure of height and weight. But this week, two major medical journals published articles advocating against the use of the BMI to calculate mortality risk."

This is an absolutely idiotic & ignorant criticism because 'obesity' is *defined clinically* as BMI >30. You can't run a study of obesity without using BMI, because it's the measure used to define what 'obesity' is. If you want to compare 'obese' people to 'normal weight' people, you have to use BMI, because that's the standard.

I have little doubt that the articles criticizing BMI published in 'two major medical journals this week' were published in response to this study specifically.

BMI doesn't capture every detail about a person's weight in relation to their height, and no one ever claimed it did. It's not a perfect measure -- but it's the clinical standard. Furthermore, it's the measurement used in nearly every study where weight has been found to be 'unhealthy' through association with diabetes and other diseases.

Funny that in those studies no one questioned the use of BMI.