Body mass index variations by age and sex, and prevalence of overweight in Japanese adults

Abstract

OBJECTIVE: To determine the reference value of BMI for Japanese subjects and to estimate the prevalence of overweight based on this reference value. DESIGN: Epidemiological analysis with the LMS method, which provides a way of obtaining normalized BMI distributions. SUBJECTS: 7508 Japanese subjects aged 18–69 y in 1993. MEASUREMENTS: Height, age and body weight. CALCULATION: BMI was calculated and tables for percentiles of BMI were plotted against age and sex. Furthermore, the prevalence of overweight was estimated based on 85th percentile of BMI in the men and women 20–29 y of age, who were considered the reference group. RESULTS: The geometric mean BMI and the prevalence of overweight in men was highest in the 30–39 y age group. For women the maximum BMI and prevalence of overweight occurred in the decade 50–59 y. The cut-off points for overweight in this sample were 24.7 kg/m² for men and 22.6 kg/m² for women. These are considerably lower than the figures of 27.8 kg/m² and 27.3 kg/m² estimated for Americans. CONCLUSIONS: The prevalence of obesity in Japanese populations should be estimated using ethnic specific values of BMI, rather than those drawn from Caucasians who tend to have higher BMI in each age group. The prevalence of overweight is increased as age increased in both sexes, especially in women.