Use of bioelectrical impedance for the prediction of body composition in children and adolescents

The analysis of body composition constitutes the center of nutritional state evaluation. Its estimation in the pediatric area has become highly relevant due to the growing prevalence of obesity in the first stages of life and the adverse effects on health. Bioelectrical impedance is one of the methods developed to estimate body compo- sition in research as well as in clinic. Bioelectrical impedance is based on the opposition of cells, tissues or body fluids to the pass of an electric current. This method measures total body water and allows the estimation of fat and fat free body mass. Among its advantages are low cost, easy transportation and handling and low variability be- tween observers. This article makes a revision of bioelectric impedance as a technique to evaluate body composi- tion. Aspects related to its methodological assumptions are presented, as well as its advantages, limitations and applications in the estimation of body composition of children and adolescents. The applicability and validity shown by bioelectric impedance in epidemiologic studies place it next to reliable methods for the study of body composition.An Venez Nutr 2009;22 (2): 105-110.