Analysis for body composition status and development pattern of children and adolescents aged 6-17 years in Guangzhou / 中华实用儿科临床杂志

ABSTRACT

Objective:To analyze the current status of body composition and development patterns of children and adolescents aged 6-17 years in Guangzhou.Methods:This was a cross-sectional study involving 8 169 school students from 3 elementary schools and 3 middle schools in Guangzhou from March to December 2019.The fat-free mass (FFM) and fat mass (FM) were measured by the bioelectrical impedance analysis.The fat-free mass index (FFMI) and fat mass index (FMI) were calculated via the height standardization. T test was used to compare quantitative variables between groups.The growth pattern of body composition was described using the Hattori chart. Results:A total of 4 431 boys (54.24%) and 3 738 girls (45.76%) were involved in this study.FFM and FM both increased with age between boys and girls.Except for boys aged 11 years, FFM in boys were significantly higher than that in girls with the same age (all P<0.05). In the age of 7-10 years, FM in boys were significantly higher than that in girls with the same age, while it was significantly higher in girls aged 12 years and older than that of boys at the same age (all P<0.05). The Hattori chart showed that the difference in body composition between genders occurred after 11 years old.In contrast to girls, increases in the weight and body mass index (BMI) in boys were mainly attributed to the FFM development. Conclusions:The development of FFM and FM in children and adolescents varies with age, accompanied with the gender-specific features.FFM in boys is higher than that of girls at the same age.The weight gain in boys is mainly attributed to the development of fat-free tissues, and thus the utility of BMI may lead to the overestimation of obesity.