Body Mass Index Categories and Mortality Risk in US Adults: The Effect of Overweight and Obesity on Advancing Death

OBJECTIVES: We examined the association of body mass index with all-cause and cardiovascular disease (CVD)-specific mortality risks among US adults and calculated the rate advancement period by which death is advanced among the exposed groups. METHODS: We used data from the Third National Health and Nutrition Examination Survey (1988-1994) linked to the National Death Index mortality file with follow-up to 2006 (n = 16 868). We used Cox proportional hazards regression to estimate the rate of dying and rate advancement period for all-cause and CVD-specific mortality for overweight and obese adults relative to their normal-weight counterparts. RESULTS: Compared with normal-weight adults, obese adults had at least 20% significantly higher rate of dying of all-cause or CVD. These rates advanced death by 3.7 years (grades II and III obesity) for all-cause mortality and between 1.6 (grade I obesity) and 5.0 years (grade III obesity) for CVD-specific mortality. The burden of obesity was greatest among adults aged 45 to 64 years for all-cause and CVD-specific mortality and among women for all-cause mortality. CONCLUSIONS: These findings highlight the impact of the obesity epidemic on mortality risk and premature deaths among US adults.