Indirect methods for measuring body fat in adolescent students

Abstract

Objective: To compare two different indirect methods for measuring body fat percentage in adolescent students. Methods: Analytical cross-sectional study conducted with 300 adolescent students from 12 to 17 years old in the city of Petrolina, state of Pernambuco. All patients underwent anthropometric assessment. The body fat percentage was estimated through skinfold thickness and bipolar bioelectrical impedance analysis (BIA). The tests followed recommended procedures and subjects were properly dressed for the assessment. The different body fat percentages were compared using the Wilcoxon nonparametric test and correlated by Spearman’s rank correlation coefficient with a significance level of p≤0.05. Results: The median (interquartile range) age of the subjects was 13.0 (13.0–15.0) years with a total number of 214 (71.3%) girls. The compared methods showed strong positive linear correlation (r=0.76, p<0.001). However, the 26.9% (26.5–28.2) rate of fat obtained through skinfold thickness is statistically different (p<0.001) from the 22.3% (21.6–23.1) rate obtained through BIA. In both genders and at all ages the percentage of fat estimated through skinfold thickness was higher than the one estimated through BIA. However, the methods presented a good correlation (p<0.0001). Conclusion: The body fat percentage measured through anthropometric assessment (skinfold thickness) and bipolar bioelectrical impedance analysis have a strong significant correlation in adolescent students. In this context, BIA appears as an interesting option to monitor and assess changes in the nutritional status of this population doi:10.5020/18061230.2013.p412

Keywords

• Composição Corporal
• Pregas Cutâneas
• Impedância Elétrica
• Adolescente
• Obesidade.