Factors associated with being overweight among Inner Mongolia medical students in China

OBJECTIVES: A major goal of our study was to identify the associations between lifestyle factors and obesity in adolescents and young adults at risk by surveying students in Inner Mongolia Medical University. A second goal was to determine these factors differed by gender. DESIGN: Cross-sectional study. SETTING: Students grade 1–3 in Inner Mongolia Medical University. PARTICIPANTS: 5471 grade 1–3 medical students, composed of 3891 female and 1580 male students. Students with body mass index (BMI) ≥25 were defined as overweight. RESULTS: BMI for male students was 22.1±2.9 and 21.2±2.2 for female students. The prevalence of overweight was 7.6%, with the prevalence being higher for male students compared with females, urban higher than rural and being an only child higher than having sibling children. For male students, urban residence was a risk factor, while for female students being an only child and staying up at night were risk factors, with physical activity a protective factor. A dose-dependency relationship was found between physical fitness and overweight prevalence. CONCLUSIONS: This study shows that being an only child and resident in an urban area are risk factors; staying up late and lack of physical activities increased the risk of being overweight. BMI was associated with declines in physical fitness. Our study provides more insight into adolescent obesity problems.