•  
  •  
 

THE AGREEMENT OF BODY FAT PERCENTAGE ESTIMATES FROM ULTRASOUND, SKINFOLD, AND AN UNDERWATER WEIGHING CRITERION

Abstract

Katherine Sullivan, Casey J. Metoyer, Michael R. Esco, Michael V. Fedewa. University of Alabama, Tuscaloosa, AL.

BACKGROUND: Accurate measures of body composition are clinically important, as higher adiposity is associated with various unfavorable health outcomes. Ultrasound has been proposed as a viable alternative to skinfold (SKF) thickness for the estimation of body fat (%Fat) as it may overcome reliability concerns often associated with SKF measurement. However, ultrasound has not been extensively examined in generally healthy, young adults. Therefore, the purpose of this study was to examine the agreement between %Fat from ultrasound (%FatUS), skinfold thickness (%FatSKF), and an underwater weighing (%FatUWW) criterion. METHODS: A convenience sample of 46 young adults were included in our analysis (28.3% female, 82.6% Caucasian, 22.8±4.1 yrs., 24.3±3.5 kg/m2). Ultrasound and SKF measurements were taken on the same seven standardized sites on the right side of the body by the same evaluator. For each participant, two SKF and ultrasound measures were taken at each site. For each measurement site, the two SKF and ultrasound measures were averaged. The averaged SKF site measures were then summed. The averaged ultrasound site measures were converted to millimeters, doubled, and then summed. The sum of SKF and ultrasound measures were used separately to calculate body density via the gender specific Jackson and Pollock equations. Body density via underwater weighing (UWW) served as the criterion measure. Subsequently, %FatUS, %FatSKF, and %FatUWW were calculated using the Siri equation (%Fat = [495/body density] - 450). A repeated measures ANOVA examined potential differences between %FatUS, %FatSKF, and %FatUWW. Data are presented as mean ± standard deviation, with p<0.05 used to determine statistical significance. RESULTS: A small, non-significant mean difference was observed between %FatUS (19.3±9.1 %Fat) and %FatUWW (18.1±6.8 %Fat) (ES=0.18, p = 0.11). A small, but statistically significant, mean difference was observed between %FatSKF (19.3±7.1 %Fat) and %FatUWW (18.1±6.8 %Fat) (ES=0.18, p = 0.05). Both, %FatUS (r =.818, SEE=3.9 %Fat, p<.001) and %FatSKF (r =.808, SEE=4.0 %Fat, p<.001) yielded similar agreement with %FatUWW. CONCLUSIONS: Ultrasound and SKF were comparable to UWW when measured using Jackson and Pollock’s 7-site body density equations. However, the time burden to participants and added financial cost may not justify the utility of ultrasound within generally healthy, young adults.

This document is currently not available here.

Share

COinS