Table 5.

Age-standardized mortality rates per 1,000 person-years by BMI at survey and BMI at max

BMI category	Mortality rate, BMI at survey (95% CI)	Mortality rate, BMI at max (95% CI)	Mortality rate ratio (survey/max)
Underweight	13.53 (1.95–25.11)
Normal weight	8.11 (6.30–9.93)	6.37 (4.33–8.42)	1.27
Overweight	9.30 (7.71–10.88)	8.27 (6.44–10.10)	1.12
Obese class I	14.16 (11.11–17.21)	12.76 (10.05–15.47)	1.11
Obese class II	15.01 (11.73–18.30)	17.22 (13.92–20.53)	0.87

Underweight, less than 18.5 kg/m²; normal weight, 18.5–24.9 kg/m²; overweight, 25.0–29.9 kg/m²; obese class I, 30.0–34.9 kg/m²; obese class II kg/m² 35.0 kg/m² above. Mortality rates were age-standardized to the US 2000 Census using 5-y age groups between 50 and 84 y. For maximum BMI, there is no estimate for the underweight because of insufficient data in this category (n = 5). Estimates are weighted and account for complex survey design.