[Prediction formulas for estimating body fat percent of obesity from bioelectrical impedance]

The bioelectrical impedance method has become a popular and widely used method to determine body composition. In this study, body fat was measured by densitometry in a group of 66 males and 130 females obesity Chinese, aged 18 to 67 years. Body weight, body height were measured as well as total body bioelectrical impedance at 50 kHz. BMI and BF% was (27.7 +/- 3.1) kg/m2 and (38.81 +/- 6.27)% respectively (mean +/- SD). The prediction formulas for body fat from bioelectrical impedance developed in western societies, are significant underestimate body fat of Chinese obesity from body density. The prediction formulas for body fat with our subjects is; BF = 0.846 * Wt - 0.185 * Ht2/Z - 2.361 * Sex - 24.977. (r = 0.923, SEE = 3.43, F = 365.7, P < 0.001). Wt: body weight; Ht: body height; Sex; male = 1, female = 0; Z: bioelectrical impedance.