Body mass index in a US national sample of Asian Americans: effects of nativity, years since immigration and socioeconomic status

OBJECTIVE: To examine body mass index (BMI) and the proportion overweight a nd obese among adults age 18-59 in the six largest Asian American ethnic gr oups (Chinese, Filipino, Asian Indian, Japanese, Korean, Vietnamese), and i nvestigate whether BMI varies by nativity (foreign- vs native-born), years in US, or socioeconomic status. DESIGN: Cross-sectional interview data were pooled from the 1992-1995 Natio nal Health Interview Survey (NHIS), SUBJECTS: 254,153 persons aged 18-59 included in the 1992-1995 NHIS. Sample sizes range from 816 to 1940 for each of six Asian American ethnic groups. MEASUREMENTS: Self-reported height and weight used to calculate BMI and cla ssify individuals as overweight (BMI greater than or equal to 25 kg/m(2)) o r obese (BMI greater than or equal to 30 kg/m(2)), age, sex, years in the U S, household income and household size. RESULTS: For men, the percentage overweight ranges from 17% of Vietnamese t o 42% of Japanese, while the total male population is 57% overweight. For w omen, the percentage overweight ranges from 9% of Vietnamese and Chinese to 25% of Asian Indians, while the total female population is 38% overweight, The percentage of Asian Americans classified as obese is very low. Adjuste d for age and ethnicity, the odds ratio for obese is 3.5 for women and 4.0 for men for US - vs foreign-born. Among the foreign-born, more years in the US is associated with higher risk of being overweight or obese. The associ ation between household income for women is similar for US-born Asian Ameri cans and Whites and Blacks, but is much weaker for foreign-born Asian Ameri cans. CONCLUSIONS: While these data find low proportions of Asian Americans overw eight at present, they also imply the proportion will increase with more US -born Asian Americans and longer duration in the US.