Relationship between skinfold and optical density at upper and lower body measurement sites

Abstract

This study examined the relationship between Skinfold (SKF) and Optical Density (OD) at upper and lower body sites in 20 active (>30 mins per day) male subjects (19-34 years). The use of lower body measurement sites in regression equations developed to predict %BF was also investigated. Percent Body Fat (%BF) was calculated by Hydrostatic Weighing (HW), SKF and Near Infrared Interactance (NIR) using the Futrex 5000. SKF and OD measurements were taken at ten anatomical sites. Estimations of %BF by SKF and NIR were found to be significantly different (p<0.05) from %BF by HW. OD1 and OD2 values generated from NIR and SKF thicknesses at each site were found to be poorly correlated in this population. Regression equations developed from SKF and OD data found that upper body sites were generally the best predictors of %BF (r2=.63, SEE +/- 2.15%). A combination of upper and lower body SKF and OD sites showed good predictive accuracy for Fat mass (r2=.96, SEE +/- .97Kg) and Fat Free Mass (r2=.98, SEE +/- .87Kg). In the population studied upper body measurement sites were generally the better predictors of %BF.