January 2, 2013

Don’t let your BMI scare you (too much)

Filed under: Health, Media — Tags: , , , , — Nicholas @ 10:47

A quick reminder that the Body Mass Index (BMI) is more a convenient mathematical trick than an actual healthy weight guideline:

In a finding that could undermine many New Year’s resolutions, a new government study shows that people who are overweight are less likely to die in any given period than people of normal weight. Even those who are moderately obese don’t have a higher-than-normal risk of dying.

Being substantially obese, based on measure called body mass index, or BMI, of 35 and higher, does raise the risk of death by 29%, researchers found.

But people with a BMI of 25 to 30 — who are considered overweight and make up more than 30% of the U.S. population — have a 6% lower risk of death than people whose BMI is in the normal range of 18.5 to 25, according to the study, being published Wednesday in the Journal of the American Medical Association.

People who had a BMI of 30 to 35 — considered the first stage of obesity — had a 5% lower risk of dying, but those figures weren’t considered statistically significant.

In other words, a few extra pounds are not going to threaten your life (a lot of extra pounds might). In the western world, few of us have the kind of jobs that require much in the way of physical exertion and we also have both relatively low food prices and much greater access to calorie-dense food. Our parents tended to have jobs that required more physical effort and their access to food was not as great as ours (they were less wealthy overall, and didn’t eat at restaurants or fast food joints as often as we do). Two otherwise positive trends that combine to produce a less-positive result on the scales.

Earlier discussion of the limitations of BMI as a guideline here, here, here, and here.

No Comments

No comments yet.

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.

Powered by WordPress