Regional body volumes, BMI, waist circumference, and percentage fat in severely obese adults.

Abstract

This study presents total body volume (TBV) and regional body volume, and their relationships with widely used body composition indices [BMI, waist circumference (WC), and percentage body fat (% fat)] in severely obese adults (BMI >or=35 kg/m(2)). We measured TBV, trunk volume (TV), arm volume (AV), leg volume (LV), and WC and estimated % fat in 32 severely obese persons with BMI 36 to 62 kg/m(2) (23 women; age, 19 to 65 years; weight, 91 to 182 kg) and in 58 persons with BMI <35 kg/m(2) (28 women; age, 18 to 83 years; weight, 48 to 102 kg) using a newly validated 3-day photonic image scanner (3DPS, Model C9036-02, Hamamatsu Co., Japan) and calculated TV/TBV, AV/TBV, and LV/TBV. Men had significantly larger TBV and higher TV/TBV and AV/TBV, but significantly lower LV/TBV than women, independently of BMI. TV/TBV increased while AV/TBV and LV/TBV decreased with increasing BMI, WC, and % fat, and the rate of increase in TV/TBV per % fat was significantly greater in severely obese individuals than in individuals with BMI <35 kg/m(2). The relationships for TBV with % fat were much lower than with BMI or WC. Body volume gains were mainly in the trunk region in adults, irrespective of sex or BMI. For a given BMI, WC, or % fat, men had a significantly larger TV than women. The implication is that men could have higher health risks due to having higher trunk body weight as a proportion of total body weight compared with severely obese or less severely obese women.