Body fat assessment in Sri Lankan adolescent girls; development of a simple field tool

Background: Development of accurate, simple measures of body fat is essential in developing countries due to the rising prevalence of overweight and obesity. Application of skin-fold thickness (SFT) to body fat prediction equations is an inexpensive method suitable for field settings. Aim: To determine percentage fat mass (%FM) of Sri Lankan adolescent girls using Fourier Transform Infrared spectrometry (FTIR) as a reference method and develop a SFT-prediction equation to estimate %FM. Methods: Weight, height and SFT were measured and %FM determined by FTIR in 131 adolescent, post-menarcheal girls (15-19 years). SFT-measurements were applied to available body composition equations for validation in the population. A new equation for % FM was derived and validated. Results: Mean % FM (FTIR) was 19.13 +/- 8.2. Selected body composition prediction equations over-estimated %FM. The multiple regression procedure yielded a final equation consisting of two anthropometric and one demographic variable, %FM = 9.701 - (0.460)* age + (0.640)*TricepsSFT + (0.583)*Supra-iliacSFT. Conclusions: Existing SFT prediction-equations are unsuitable for predicting %FM in this population. The new equation utilizing one peripheral and one truncal skin-fold, is appropriate for prediction of %FM in this population and may be applicable to other South Asian/Asian-Indian adolescents following validation.