Abstract
Objective: The incidence of obesity has been increasing in the Asia-Pacific region, but many areas do not have access to expensive medical devices for evaluating body composition. Bioelectrical impedance analysis (BIA) can precisely and easily estimate percentage body fat (%BF), regardless of social environment. The purpose of this study was to evaluate differences in body composition among ethnic groups living in rural areas in the Asia-Pacific region, and to analyze associations between body mass index (BMI) and %BF as measured by BIA. Methods: A total of 869 middle-elderly adults (Japanese: 131 men, 435 women; Palauan: 42 men, 49 women; Thai: 106 men, 106 women; mean age, 58 years; range, 40-69 years) were recruited from rural areas in Thailand, Koror Island in Palau, and Goto Island in Japan. Weight and %BF were estimated using BIA. Height was measured and BMI was calculated. Results: Weight, BMI, and %BF clearly differed among ethnic groups and by gender (p<0.0001). In each ethnic group, %BF was significantly correlated with BMI for each sex (men: Japanese, r=0.691, p<0.0001; Palauan, r=0.892, p<0.0001; Thai, r=0.842, p<0.0001; women: Japanese, r=0.892, p<0.0001; Palauan, r=0.892, p<0.0001; Thai, r=0.779, p<0.0001). Conclusions: BIA offers a reliable option for measuring %BF and a strong association exists between %BF and BMI for individuals in rural areas of the Asia-Pacific region, regardless of ethnicity.
