Body mass index and skinfolds as indicators of obesity in schoolchildren aged 8 to 10 years

Abstract

The aim of this study was to compare the concordance of two obesity indicators, BMI and % body fat in boys and girls. Therefore, 100 girls and 100 boys, with ages ranging from 8 to 10 years, were submitted to anthropometric measurements for subsequent calculation of Body Mass Index (BMI) and % body fat, both as obesity indicators. The variables were analyzed with relation to the reference criteria proposed by Williams et al and Cole et al. The results were then analyzed with the kappa index, elucidating that 79% of the boys and 85% of the girls were classified simultaneously by both procedures. The kappa index indicated a moderate agreement between the two obesity indicators for obese and non-obese classification. However, our data demonstrated that 21% of the boys and 15% of the girls showed normal weight according to BMI, but were classified as obese according to the % body fat. The results show that BMI, when compared with skinfolds, had moderate agreement in children from 8 to 10 years old for detecting obesity.