Agreement between skinfold-predicted percent fat and percent fat from whole-body bioelectrical impedance analysis in children and adolescents.

Purpose: The purpose of the study was to determine the agreement of percent body fat estimates and obesity classification derived via whole-body bioelectrical impedance analysis (% BF-BIA) with percent body fat estimates and obesity classification from skinfolds (% BF-SF) in children and adolescents.

Methods: BIA and SF data were collected on 609 boys and 645 girls aged 7 to 14 years.

Results: Although moderate correlations were observed between the measures, Bland-Altman analyses revealed fixed and proportional bias, and 95% limits of agreement covered a range of over 20% BF. Agreement of obesity classification was moderately high in boys (Kq = 0.77) and girls (Kq = 0.81), but fewer children were classified as obese via % BF-BIA (14.5%) than via % BF-SF (19.8%).

Conclusions: The results indicate that whole-body BIA provides % BF estimates that are systematically different from % BF estimates from skinfolds in children and adolescents.