Research on Body Composition and Lifestyle Behaviors During Pubertal Development in 6–12-Year-Old Children with Obesity

Objective: The objective of this study was to investigate the pubertal development in school-age children with obesity and to explore the body composition and lifestyle behaviors influencing its onset. Method: We enrolled 217 children, aged 6–12 years, who visited the Pediatrics Department at Beijing Jishuitan Hospital, Capital Medical University. All participants underwent a series of examinations. These assessments included body composition analysis, measurement of blood glucose and fasting insulin levels, and evaluation of secondary sexual characteristics. Statistical analysis was conducted using R4.0.3 software. Results: Of the 152 male participants, 83 (54.6%) were in the adolescent-undeveloped group, and 69 (45.4%) were in the adolescent-developed group. Of the 119 female students, 30 (25.2%) were in the adolescent-undeveloped group, and 89 (74.8%) were in the adolescent-developed group. In a comparative analysis of children, those in the adolescent development group exhibited significantly higher values for age, height, weight, body mass index (BMI), BMI-z score, body fat, muscle mass, fat-free weight, fat-free body mass index, and waist/hip ratio compared to the adolescent-undeveloped group (p < 0.05). Additionally, fasting insulin and insulin resistance index were also higher in the development group, with statistical significance observed. BMI emerged as an independent factor affecting the adolescent development of school-age girls with obesity (p < 0.05). Among boys in the adolescent development group, the consumption of sugary drinks and fried food was higher than in the undeveloped group, and moderate-intensity exercise was significantly lower, with statistical significance (p < 0.05). In girls, the adolescent development group reported longer daily sitting times and higher intakes of sugary drinks and fried foods compared to the undeveloped group, with these differences being statistically significant (p < 0.05). The consumption of fried food was positively correlated with adolescent development in children with obesity and was identified as an independent influencing factor of adolescent development (p < 0.05). Conclusions: A high body mass index (BMI) in girls with obesity and high intake of fried foods in both genders are strong predictors of early puberty in school-age children.