Birth weight, skeletal maturity and dietary patterns are associated with body composition compartments differently in male and female physically active adolescents.

Background: Adequate body composition is important for health and performance of physically active adolescents; however, some factors can influence body composition. Aim: The purpose of this study was to evaluate the association between body composition and birth weight, skeletal maturity and dietary patterns, in male (n = 124) and female (n = 107) physically active adolescents. Methods: Birth weight was obtained from health booklets. Dual-energy X-ray absorptiometry (DXA) was used to estimate fat mass (FM), fat-free mass (FFM), visceral adipose tissue (VAT) and abdominal adipose tissue (ASAT). Skeletal maturity was assessed by a hand and fist scanner using DXA. Food intake was assessed using a food frequency questionnaire and dietary patterns by factorial analysis. Results: Seventy one percent (male = 16%, female = 55%) of the participants were mature. Two dietary patterns ( in natura /minimally processed and processed/ultra-processed) were identified. In males, FM (>15%, P  = 0.043) and ASAT (>30%, P  = 0.042) were higher in those with low-median compared to high-median birth weight. FFM (>24%) was higher in skeletally mature compared to those immatures ( P  = 0.001), and VAT (>28%) was higher in processed/ultra-processed compared to in natura /minimally processed dietary patterns ( P  = 0.015). In females, FFM (>9%) was higher in those with low-median compared to high-median birth weight ( P  = 0.019); and FFM (>16%), FM (>28%) and ASAT (>45%) were higher in skeletally mature compared to those immatures ( P  = 0.001). Conclusion: Our results may contribute to a better understanding of the complex association among body composition, birth weight, skeletal maturity and dietary patterns and in physically active adolescents, differently according to sex.