Objective To estimate the number of deaths, annually, attributable to obesity among US adults.

Design Data from 5 prospective cohort studies (the Alameda Community Health Study, the Framingham Heart Study, the Tecumseh Community Hearth Study, the American Cancer Society Cancer Prevention Study I, and the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study) and 1 published study (the Nurses' Health Study) in conjunction with 1991 national statistic; on body mass index distributions, population size, and overall deaths.

Subjects Adults, 18 years or older in 1991, classified by body mass index (kg/m(2)) as overweight (25-30), obese (30-35), and severely obese (>35),

Main Outcome Measure Relative hazard ratio (HR) of death for obese or overweight persons.

Results The estimated number of annual deaths attributable to obesity varied with the cohort used to calculate the HRs, but findings were consistent overall. More than 80% of the estimated obesity-attributable deaths occurred among individuals with a body mass index of more than 30 kg/m(2). When HRs were estimated for all eligible subjects from ail 6 studies, the mean estimate of deaths attributable to obesity in the United States was 280 184 (range, 236 111-341 153),Hazard ratios also were calculated from data for nonsmokers or never-smokers only. When these HRs were applied to the entire population (assuming the HR applied to all individuals), the mean estimate for obesity-attributable death was 324 940 (range, 262 541-383 410).

Conclusions The estimated number of annual deaths attributable to obesity among US adults is approximately 280 000 based on HRs from all subjects and 325 000 based on HRs from only nonsmokers and never-smokers.