Body mass index and body composition in relation to sexual maturation.
To assess body mass index. (BMI) in relation to sexual maturation and verify how fat-free mass (FFM) and fat mass (FM) contribute to its increase.



1,275 White adolescents (656 girls and 619 boys), aged 9 to 18 years, were evaluated according to Tanner stages. FFM and FM were calculated by triceps and subscapular skinfold measurements and leg-to-leg bioelectrical impedance. BMI-for-maturation was distributed into percentiles. Fat-free mass index (FFMI) and body fat mass index (BFMI) were calculated based on BMI 50t" ph percentile values.



During maturation, as BMI increases, girls gain FFMI (13.3 kg/m2 at B1 and 15.8 kg/m2 at B5) and BFMI (3.7 kg/m2 at B1 and 5.7 kg/m2 at B5)--proportionally more fat-- while boys gain FFMI (14.3 kg/m2 at G1 and 17.9 kg/m2 at G5) and lose BFMI (4.8 kg/m2 at G1 and 3.2 kg/m2 at G5).



These data suggest that FFMI and BFMI-for-maturation should be assessed in adolescents monitored for overweight and obesity.
Castilho
Silvia Diez
SD
Department of Pediatrics, Faculdade de Medicina da Universidade Católica de Campinas, SP, Brazil. sdiezcast@puc-campinas.edu.br
Cocetti
Monize
M
de Azevedo Barros Filho
Antonio
A
D000273:Adipose Tissue; D000293:Adolescent; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012741:Sexual Maturation / Q000502:physiology*