Table 3.
Expected age at death for a never-smoker aged 40 years by WHO BMI category,19 and estimated reduction in life expectancy compared with an individual of healthy weight
|
Men |
Women |
||||
|---|---|---|---|---|---|
| Expected age of death at age 40 years (years) | Reduction in life expectancy (years) | Expected age of death at age 40 years (years) | Reduction in life expectancy (years) | ||
| Underweight (<18·5 kg/m2) | 77·9 | 4·3 | 79·8 | 4·5 | |
| Healthy weight (18·5–24·9 kg/m2) | 82·2 | .. | 84·3 | .. | |
| Overweight (25·0–29·9 kg/m2) | 81·2 | 1·0 | 83·5 | 0·8 | |
| Obese (all, ≥30·0 kg/m2) | 78·0 | 4·2 | 80·9 | 3·5 | |
| Obese class 1 (30·0–34·9 kg/m2) | 78·7 | 3·4 | 81·9 | 2·4 | |
| Obese class 2 (35·0–39·9 kg/m2) | 76·2 | 5·9 | 79·6 | 4·7 | |
| Obese class 3 (≥40·0 kg/m2) | 73·1 | 9·1 | 76·6 | 7·7 | |
Expected age of death at age 40 years estimated from a Poisson model for overall survival with six-category BMI variable, 5-year age bands, sex, and interaction terms for BMI with age at BMI, and BMI with sex (see appendix for details); estimates assume mortality observed in the study remains constant. Reduction in life expectancy is calculated as expected age of death minus expected age at death in the healthy weight category.