COMPARISON OF BODY FAT PERCENTAGES FROM HAND-HELD VS STAND-ON BIOELECRTICAL IMPEDANCE ANALYSIS DEVICES

Abstract

COMPARISON OF BODY FAT PERCENTAGES FROM HAND-HELD VS STAND-ON BIOELECRTICAL IMPEDANCE ANALYSIS DEVICES K.D. Oldham, W. Papin, S. G. Owens, Western Carolina University, Cullowhee, NC, e-mail: [email protected] Body composition analysis in non-research settings often utilizes bioelectrical impedance analysis (BIA). Commercial BIA devices differ from one another in a variety of ways including body segments utilized for analysis, electrode contact points, body fat prediction equations, and cost. Hence, judging the reliability, validity, and cost effectiveness of BIA devices can be a challenge. PURPOSE To compare estimates of percent body fat obtained from two commercial BIA devices: a relatively expensive, lower extremity, stand-on device and a relatively inexpensive, upper extremity, hand-held device. METHODS Participants were 74 male and female volunteer subjects (mean ± SD, age: 38 ± 16 y; body mass: 72.9 ± 13.1 kg). Percent body fat was determined, in random order and in duplicate, using a stand-on BIA device and a hand-held BIA device. The Bland-Altman procedure for comparing methods of measurement was applied to the data. A priori it was determined that the agreement between the two devices would be acceptable for non-research purposes if the “limits of agreement” (mean difference between methods ± 2SD) did not exceed ± 8 percent. RESULTS Both BIA devices showed high reliability (r > 0.99). In the percent body fat comparison, the bias (mean difference in percent body fat between the two BIA devices) was −1.03 (lower values from hand-held device) and the SD of the differences was 5.28. The limits of agreement extended from −11.59 to + 9.53 percent, and, therefore, exceeded the a priori limits of ± 8 percent. CONCLUSION Although both BIA devices showed good reliability, the devices did not agree sufficiently to be used interchangeably. Main advantages of the hand-held device included convenience (shoes and socks do not need to be removed; eye-level display) and lower cost, both of which may be important considerations in wellness/fitness center environments.