Evaluation of leg-to-leg BIA in assessing body composition in high-school-aged males and females.

The current investigation was conducted to evaluate the accuracy of the Tanita 300WA leg-to-leg (LL) bioelectrical impedance analyzer (BIA) for measuring body composition in an American high-school-aged population. Body composition was determined in 77 students, comparing BIA measurements with the criterion, hydrostatic weighing (HW). Among the males, there were no significant differences found in percent body fat (%BF) between BIA (14.1 +/- 7.8%) and HW (14.9 +/- 9.1%); however, skinfolds (SK; 11.8 +/- 7.2%) were significantly different from HW. A significant correlation in fat-free mass (FFM) was found between BIA and HW (r = 0.96, p < 0.001), and the standard error of estimate (SEE) for FFM was 3.28 kg for males. In females, a significant difference (p < 0.001) in %BF was found for both BIA (26.4 +/- 5.7%) and SK (27.9 +/- 5.1%) when compared with HW (23.6 +/- 5.9%). The correlation in FFM between BIA and HW was lower (r = 0.78, p < 0.001) and the SEE for FFM was 2.93 kg for females. The Tanita 300WA LL-BIA system is appropriate for assessing body composition in male adolescents, but it warrants future research in female adolescents.