Validity of single-site and multi-site models for estimating body composition of women using near-infrared interactance.

The purpose of this study was to develop a multi-site near-infrared (NIR) model (Model I) and compare its predictive accuracy to single-site models (IIA and IIB). In Model I, the sum of two optical density (OD) measures (Σ2OD), age, body weight, height, and physical activity level were used as potential predictors of body density (D ). In Model IIA, the variables used in the manufacturer's NIR equation (biceps OD and OD , body weight, height, gender, and physical activity level) were the potential predictors.