COMPARISON OF THREE BODY FAT PREDICTION EQUATIONS VS. AIR DISPLACEMENT PLETHYSMOGRAPHY IN OVERWEIGHT AND OBESE MALES

J.R. Brown1, L.M. Young2 1University of Utah, Salt Lake City, UT; 2University of Montana Western, Dillon, MT The body adiposity index (BAI) was developed by Bergman as an alternative to the BMI. In that study, authors utilized a population of Mexican–American and African American subjects from the southwest region of the United States with varying BMI. For this study, we examined Caucasian adult males from the state of Utah.PURPOSE: To examine the difference in body fat percentage (PBF) using Air Displacement Plethysmography (ADP) and three prediction equations (BAI, BAIFELS, BFDURN). We also sought to examine the level of agreement among the various methods used to PBF. METHODS: Adult males (N=452, 37.15 ± 9.91yr; 28.99 ± 3.36 kg/m2BMI; 27.20 ± 7.70 body fat %; 94.99 ± 10.52 cm waist circumference and 100.24 ± 8.95 cm hip circumference) volunteered for data analysis. Prior to measurement, the ADP equipment was calibrated according to manufacturer’s specifications and participants were asked to void the bladder and change into skin tight clothing. A wall-mounted stadiometer was used to measure height and an anthropometric measuring tape was used to measure hip and waist circumference to the nearest 0.1 cm. Body mass was measured to the nearest 0.01 kg using an electronic scale attached to the ADP equipment. A prediction equation was used to assess thoracic gas volume. PBF was predicted using BAI with the following equation:= [hip circumference/height1.5] – 18. PBF using BAIFELSwas predicted with the following equation:= 1.26*[hip circumference/height1.4] – 32.85, and 1.2*BMI+0.23*age-10.8*sex-5.4 (Note: For sex male =1 and female = 0). RESULTS: PBF, BAI, BAIFELS, BFDURNwere 27.20 ± 7.70, 23.92 ± 4.85, 23.12 ± 6.28 and 27.13 ± 4.85, respectively. Repeated Measures ANOVA found a significant difference in body fat percentage between methods. Bonferroni post hoc analysis revealed BAI and BAIFELSwere significantly lower than PBF. There was no difference between the PBF and BFDURN. Significant correlations were greater between all measures and PBF. CONCLUSION: These results show BAI and BAIFELSsignificantly underestimate PBF compared to BFDURNand ADP. Furthermore, Bland-Altman plots suggest poor agreement