Validação de uma balança de impedância bioelétrica para a estimativa de gordura corporal em adolescentes

Abstract

Several different instruments available on the market have been used for the estimation of body fat. However, many of these instruments have not been compared with reference criteria to verify their true accuracy. This study aimed to verify the validity of a bioelectrical impedance scale (OMRON-514C) for the estimation of body fat. Forty-four overweight adolescents (25 females) participated in this study, with an average age of 12.3 ± 1.1 years. All were submitted to body fat evaluations by air displacement plethysmography and bioelectrical impedance. Higher values of relative and absolute body fat were estimated by bioelectrical impedance compared to plethysmography (p < 0.05). There was no correlation between the relative body fat measurements between the two methods (r = 0.185; p = 0.228). The absolute measurements of body fat were correlated (r = 0.497, p = 0.001). Both in the measurements of relative (p= 0.034) and absolute body fat (p = 0.021), the bioelectrical impedance overestimated the measured values. Thus, in adolescents with characteristics similar to the present study, the estimate of body fat by the bioelectrical impedance (OMRON-514C) should be used with caution.Keywords: plethysmography, bioelectrical impedance, adolescents, overweight.

Agreement and validity between body fat estimated by skinfold measurement and air displacement plethysmography in adolescents

“…There was no agreement between methods for adolescents with overweight of either sex, corroborating the results of Pelegrini et al 23 , who did not observe agreement between bioelectric impedance analysis (BIA) and ADP for adolescents with overweight. These results suggest that, although skinfold equation are recommended because of their greater simplicity and feasibility when evaluating adolescents with overweight, it is pertinent to consider additional body measures (body perimeters or other indicators, such as waist-toheight ratio and body adiposity index) for better interpretation of body composition.…”