{"id":2704,"date":"2006-09-14T13:40:58","date_gmt":"2006-09-14T20:40:58","guid":{"rendered":"http:\/\/www.amptoons.com\/blog\/archives\/2006\/09\/14\/will-being-a-few-pounds-overweight-kill-you\/"},"modified":"2006-09-14T13:40:58","modified_gmt":"2006-09-14T20:40:58","slug":"will-being-a-few-pounds-overweight-kill-you","status":"publish","type":"post","link":"https:\/\/amptoons.com\/blog\/?p=2704","title":{"rendered":"Will being a few pounds overweight kill you?"},"content":{"rendered":"

On Monday<\/a>, I wrote about a recent study, published in the New England Journal of Medicine ((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<\/em>, 2006. 355(8): p. 763-8. )) , which is intended to refute last year’s CDC study<\/a> (published in JAMA ((Flegal, K.M., et al., Excess deaths associated with underweight, overweight, and obesity. Journal of the American Medical Association<\/em>, 2005. 293(15): p. 1861-7. There are “Alas” posts discussing this study here <\/a>and here<\/a>.)) ) showing that “overweight” people live longer than “normal” weight people.<\/p>\n

According to media reports, this new study proved that even a slight weight gain can be deadly. The AP<\/a> wrote “Being a little overweight can kill you, according to new research that leaves little room for denial that a few extra pounds is harmful.” NPR <\/a>wrote “being even a bit overweight can potentially kill you.” The Star-Ledger<\/a> ominously asked “Those few extra pounds won’t kill you … or will they?”<\/p>\n

The NEJM study, by Adams et al., is — frankly — a badly conducted study. It uses a non-representative sample (members of The American Association of Retired People, or AARP) with an incredibly low response rate of 18%. Even worse, height and weight were self-reported.<\/p>\n

But for the study’s authors, who were determined to come up with a study proving that fat equals death, the data presented a much more serious problem: the people in the “overweight” category were longer-lived than the people in the “normal weight” category. How to spin data showing that overweight people live longer, into their desired message that fat is always deadly?<\/p>\n

In Monday’s post, I quoted Linda Bacon extensively. Today I want to expand on one of her points:<\/p>\n

…Let\u2019s take a look at the data itself. The authors worked hard for their conclusion. They examined records from over a half million AARP members that had been surveyed over a ten year period. What they found was entirely consistent with the earlier JAMA report: \u201coverweight\u201d people had the lowest mortality risk. But that wouldn\u2019t serve their purposes. NEJM\u2019s press release wouldn\u2019t look nearly as attractive with that headline.<\/p>\n

So they subjected their data to numerous manipulations before finally arriving at a suitable conclusion. First they threw out data on people who were smokers or former smokers. Nope, still shows overweight as benign. They hid this with a sleazy method: using only the top (BMIs of 23 to 24.9) of the \u201cnormal weight\u201d group compared to the whole of the \u201coverweight\u201d group.<\/p><\/blockquote>\n

Here’s a table of some of the relative risks reported in the Adams et al. study (if you have trouble reading it, click on the image for a larger version):<\/p>\n

\"Relative<\/a><\/p>\n

The yellow column indicates the relative risk of death for “normal weight” people (the heaviest set of “normal” weight people are used as the baseline; all other risk ratios on this table are in comparison to those folks). The red outlines indicate the areas where the relative risk of death is as low or lower<\/em> for “overweight” people as it is for “normal weight” people.<\/p>\n