Kaplan Meier curves for categories of BMI at time of survey and at maximum. Categories of BMI are normal weight (18.5-25.0 kg/m2); overweight (25.0-29.9 kg/m2); obese class 1 (30.0-34.9 kg/m2); and obese class 2 (35.0 kg/m2 or greater). The sample includes persons ages 50-84 who never smoked. Entry years are 1988-2004 with mortality follow-up through 2006. Estimates are weighted and account for complex survey design. Source: National Health and Nutrition Examination Survey.