Comparison of body fat measurement techniques in females

The main objective of this study was to assess the accuracy of the Tanita-TBF 305 foot-to-foot bioelectrical impedance analyzer for the estimation of body composition as compared to hydrostatic weighing. The secondary objective of this investigation was to access the impact of waist-to-hip ratio (WHR) on the estimation of body composition by the Tanita foot-to-foot analyzer. Participants were 40 pre-menopausal, obese females (39.7 ± 7.8 yrs; 46.5 ± 1.0% BF). In addition, the subjects were sub-divided based on WHR: 1) ≤ 0.75 lower body obesity (LBO); 2) ≥ 0.85 upper body obesity (UBO); 3) between 0.75 and 0.85 overall obese group. The results showed no significant differences in anthropometric characteristics between the sub-groups except for WHR (p < 0.0001). Estimation of body composition variables such as fat-free mass (FFM), fat mass (FM), and % body fat (BF) were obtained with the Tanita TBF-305 and hydrostatic weighing (HW). There were no significant differences for the total sample (n=40) in FFM, FM, or %BF between methods. Further, there was a significant correlation between HW and foot-to-foot BIA for FFM (r = 0.70), FM (r = 0.93), and %BF (r = 0.55) (p < 0.001). The standard error of the estimate for %BF was 5.6%. A repeated measures ANOVA showed no significant influence of body shape (i.e., WHR) on the prediction of %BF (p = 0.77). Correlation analysis revealed no relationship between WHR and the difference m %BF between methods (r = 0.03, p = 0.85) for the entire sample. In conclusion, the Tanita TBF-305 has the ability to accurately predict body composition m obese, pre-menopausal females. Furthermore, deviations in body shape (i.e., WHR) have no significant influence on the ability of the Tanita TBF-305 to estimate body composition.