Combined effects of obesity and physical activity in predicting mortality among men.

OBJECTIVE: We evaluated the hypothesis that higher levels of total daily physical activity can eliminate the increased mortality rate associated with overweight and obesity.

DESIGN: Population-based prospective cohort study.

SETTING: Central Sweden.

SUBJECTS: A total of 37,633 men at baseline 45-79 years of age and free of known cancer and cardiovascular disease and diabetes completed a self-administered life-style questionnaire, which included questions on body-mass index (BMI) and physical activity. During 9.7 years of follow-up, we identified a total of 4086 deaths.

MAIN OUTCOME MEASURES: Mortality rate ratios (RRs).

RESULTS: Compared to men who were lean (BMI < 25 kg m(-2)) and active (top tertile of total physical activity level) the multivariable adjusted RRs (95% confidence interval) of death from all causes were 1.44 (1.11-1.86) for obese (BMI > or = 30 kg m(-2)) and active men, 1.54 (1.34-1.77) for lean (BMI < 25 kg m(-2)) but inactive (bottom tertile) men, and 1.81 (1.48-2.23) for obese-inactive men. After excluding the first 3 years of follow-up, current and former smokers, those who had lost weight from age 20 years to age at baseline, and heavy manual workers, the adjusted RRs of death from all causes were 1.65 (1.20-2.27) for overweight-to-obese and active men, 2.15 (1.59-2.91) for lean-inactive men, and 2.04 (1.52-2.74) for overweight-to-obese and inactive men compared to lean-active men.

CONCLUSIONS: We conclude that both overweight and physical inactivity are important predictors of mortality. Our findings do not support the hypothesis that a higher level of physical activity compensates the excess mortality associated with overweight and obesity.