Contribution of obesity to international differences in life expectancy.

Abstract

The United States has the highest prevalence of obesity and one of the lowest life expectancies among high-income countries. We investigated the relationship between these 2 phenomena. We estimated the fraction of deaths attributable to obesity by country, age, and sex and reestimated life tables after removing these deaths. To allow for a possible secular decline in obesity risks, we employed alternative risks from a more recent period. In our baseline analysis, obesity reduced US life expectancy at age 50 years in 2006 by 1.54 years (95% confidence interval [CI] = 1.37, 1.93) for women and by 1.85 years (95% CI = 1.62, 2.10) for men. Removing the effects of obesity reduced the US shortfall by 42% (95% CI = 36, 48) for women and 67% (95% CI = 57, 76) for men, relative to countries with higher life expectancies. Using more recently recorded risk data, we estimated that differences in obesity still accounted for a fifth to a third of the shortfall. The high prevalence of obesity in the United States contributes substantially to its poor international ranking in longevity.