The decline in the United States mortality rate has been slowed by a rise in deaths due to complications related to obesity, defined as a body mass index (BMI) of 30 or higher. Between 1988 and 2011, the percentage of United States adults aged 40 to 79 who had been obese at some point in their lives increased from 39.8% in 1988 to 52.0% in 2011. The increase in the number who had been obese is estimated to have reduced United States life expectancy at age 40 by 0.9 years in 2011. These findings were reported in . . .