Best published equation for the calculation of Body Fat in a sample of Colombian young males using Bioelectrical Impedance Analysis

Abstract

With the worldwide epidemic growth of obesity prevalence, nutritional assessment has become of paramount importance, both clinically and epidemiologically. Bioelectrical Impedance Analysis (BIA) is an alternative for the calculation of % Body Fat (%BF), but, so far, it requires population specific predictive formulae [1]. Until these are developed for the Colombian population, we wanted to know which of the published formulae could be best used in our region. Six of them were selected to calculate %BF from BIA measurements taken at 50 kHz with a Xitron 4000B Bio-Impedance Analyzer and the results compared against %BF calculated from skin fold (SF) measurements with a Skyndex I calliper, according to Durnin and Womersley [2]. Subjects were 68 healthy young male volunteers (average age: 20.03 y, range 18.04 – 24.85 y), recruited among students at the University of Caldas- Manizales-Colombia. The Bland and Altman method [3] was used to determine the agreement between BIA and SF for the calculation of %BF. Best results were obtained with the van Loan and Mayclin [4] formula (mean difference -0.84, percentage points with 95% confidence interval -5.91 and 4.24), but they suggest the necessity of developing our own predictive formulae if we are to use BIA and SF interchangeably.