Anthropometric indices as predictors of percentage body fat in adolescents

Regarding to the impact of childhood and adolescence obesity on incidence of most of chronic adulthood diseases, determination of the predictors of obesity can play an important role in human health. Therefore, the objective of the present study was to compare body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), waist to height ratio (WHtR) and skinfolds as predictors of percentage body fat (PBF) and diagnosis of excess adiposity in Iranian adolescents. In this cross-sectional study, all anthropometric measurements and PBF using the bioelectrical impedance analysis of 133 adolescents (65 boys and 68 girls), aged 10-18 years, were taken. Linear regression and receiver operating characteristic (ROC) analysis were used to analyze the data, adjusting for potential covariates including sex, age, and pubertal stage. BMI explained 67% of between-subject variance in PBF and R2adj of models revealed that prediction of PBF by BMI was better than other indices (P< 0.001). The AUC value for BMI to differentiate between the excess adiposity and normal PBF was 0.92 (P< 0.001), which was significantly higher than those for WC, WHR, and WHtR (P< 0.05). The performance of BMI is better than other anthropometric indices in predicting PBF and diagnosing excess adiposity in Iranian adolescents.