Obesity Can Cut Years Off Lifespan

Aug. 26, 2009— -- Extremely obese people — those who are 80 or more pounds over a normal weight — live three to 12 fewer years than their normal-weight peers, a new study shows.

Just being overweight or moderately obese, however, has little or no effect on life span, the research found. The finding adds to the growing body of evidence that being slightly overweight may have no influence on life expectancy, but being severely overweight trims years off people's lives.

Overall, about 66 percent of adults in the USA are either overweight or obese. About one-third of people are in the obese category, meaning they have a body mass index of 30 or greater.

Body mass index, or BMI, is a measure based on height and weight. About 6 percent of people are extremely obese — that is, they have a BMI of 40 or greater.

Economists with RTI International, a non-profit research organization in Research Triangle Park, N.C., analyzed national data on 366,000 people. Among the findings being published online in the journal Obesity:

The effect of extreme obesity appears to be greater for men than women and for whites than blacks, says Derek Brown, a health economist with RTI International and co-author of the study.