Acurácia de indicadores antropométricos de obesidade para predição do excesso de gordura corporal em adolescentes de onze a catorze anos

Abstract

The aim of this study was to evaluate the diagnostic accuracy of body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and conicity index (C index) for the prediction of excess body fat (estimated by skinfold thickness) and determine the cutoffs of anthropometric indicators (BMI, WC, WHtR and C index) that best predict excess body fat. Overall, 1,589 students (11-14 years old) from public and private schools of Florianopolis (southern Brazil) participated in this study. Anthropometric measurements of body weight, height, WC, and skinfolds (triceps and medial calf) were collected. ROC curves were used to compare the discriminatory power of BMI, WC, WHtR and C index in detecting adolescents with excess body fat (relative body fat estimated with skinfold thickness). All anthropometric indicators, except for C index in females, obtained good performance in the detection of excess body fat in both sexes, expressed as the area under the ROC curve. Cutoffs for boys and girls, respectively, associated with high excess body fat were BMI (20.7 and 19.7kg/m²), WC (68.7 and 65.9cm), WHtR (0.43 and 0.41cm), and C index (1.13 and 1.11). The study showed that, except for C index in females, BMI, WC and WHtR can be used to identify excess body fat in adolescents, considering the suggested cutoffs from this research.