Validity of bioelectrical impedance analysis to measure body fat in Air Force members.

This study determined if the bioelectrical impedance analysis (BIA) method was a more valid assessment of body fat in Air Force members than the current Air Force circumference (AF) method. Both methods were compared with hydrostatic weighing, which is the presumed standard for identifying body fat. Subjects included 50 male and 50 female active duty Air Force members between the ages of 19 and 47 years. The AF method had higher correlation coefficients and lower standard error of estimates for both male and female subjects (r = 0.91 [3.00%] and r = 0.79 [3.28%], respectively) than the BIA method (r = 0.84 [3.25%] and r = 0.75 [4.30%], respectively). The false-positive rates for individuals having excess body fat were greater for the AF method (14.7 and 29.3% for males and females, respectively) than the BIA method (7.3 and 8.8% for males and females, respectively). The data suggest that caution should be used when the current AF method or the BIA method is used to make individual Air Force career decisions.