The aim of this study was to compare bipolar (BI2) (frequency: 50Hz) and octapolar (BI8) (frequency: 5, 50 e 500Hz) bioelectrical impedance analyzers to estimate fat-free mass (FFM) and relative body fat (BF%) before and after 16 weeks of intervention in overweight and obese adolescents. The FFM and BF% were measured by BI2 and BI8 before and after 16 weeks of multidisciplinary intervention focused on changing eating and exercise habits. FFM and BF% obtained in the IBs were compared by ANOVA for repeated measures and correlated by Pearson Correlation Coefficient. Differences (p<0.05) were observed between the analyzers for the estimation of FFM and BF% only in the pre intervention moment for the girls. We conclude that the estimations of FFM and BF% were not significantly different between the two BI (octapolar and bipolar), especially for the variation of these two variables.
Body composition; Adolescents; Electrical impedance
