BODY-MASS INDEX VARIATIONS BY AGE AND SEX, AND PREVALENCE OF OVERWEIGHT IN JAPANESE ADULTS

OBJECTIVE: To determine the reference value of BMI for Japanese subjec ts and to estimate the prevalence of overweight based on this referenc e value. DESIGN: Epidemiological analysis with the LMS method, which p rovides a way of obtaining normalized BMI distributions. SUBJECTS: 750 8 Japanese subjects aged 18-69 y in 1993. MEASUREMENTS: Height, age an d body weight. CALCULATION: BMI was calculated and tables for percenti les of BMI were plotted against age and sex. Furthermore, the prevalen ce 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 m en 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/m(2) for men and 22. 6 kg/m(2) for women. These are considerably lower than the figures of 27.8 kg/m(2) and 27.3 kg/m(2) estimated for Americans. CONCLUSIONS: Th e prevalence of obesity in Japanese populations should be estimated us ing ethnic specific values of BMI, rather than those drawn from Caucas ians 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.