Body fat percentiles of Brazilian adolescents according to age and sexual maturation: a cross-sectional study

BACKGROUND The objective of this study was to determine body fat percentiles of adolescents in the city of São Paulo, Brazil, according to gender, age, and sexual maturation. METHODS This study involved 4,690 adolescents aged 10-15 years across 31 schools in the city of São Paulo. Sexual maturation was assessed in terms of Tanner stage. The body fat percentage was calculated using skinfold thickness. Percentile curves were calculated using the LMS (curve, mean, and coefficient of variation) method. RESULTS The mean body fat percentages were lower in boys aged 10-12 and 13-15 years than in girls. Body fat percentages decreased progressively with sexual maturation in boys, but increased in girls. The 85th, 95th, and 97th percentiles represent the cutoff points for moderately elevated, elevated, and very elevated body fat percentages, respectively, in pre-pubescent boys (85th, 95th, and 97th percentiles: 32.54, 95 41.04, and 97, respectively) and pubescent boys (31.09, 36.30, and 44.33, respectively). These cutoff points were lower in pre-pubescent girls (29.52, 35.01, and 41.82, respectively) and in the 97th percentile in pubescent girls (31.55, 36.20, and 41.86, respectively). CONCLUSION To our knowledge, these are the first body fat percentages cutoff points according to sexual maturation for adolescents aged 10-15 years in Brazil. Our results provide a significant contribution to the assessment of body composition in this population.