Prevalence and influencing factors of overweight and obesity among primary and secondary school students in Zhejiang province in 2021: a nutrition and health surveillance-based analysis

  Objective  To understand the prevalence and influencing factors of overweight and obesity among primary and secondary school students in Zhejiang province for developing relevant intervention measures.

  Methods  As a part of ′Student Nutrition Improvement Program′, on site questionnaire survey and physical examinations were conducted during September - December 2021among 5 593 primary school students (grade III and above) and secondary school students (grade III and below) recruited using a stratified cluster random sampling at 5 counties/prefectures/districts of Zhejiang province. Overweight and obesity were determined according to the standard of 'Screening for Overweight and Obesity in School-age Children and Adolescents (WS/T 586 – 2018)' issued by National Health and Family Planning Commission. Logistic regression analysis was used to analyze influencing factors of overweight and obesity.

  Results  Of the 5 220 students surveyed effectively, 15.10% (788) and 12.32% (643) were assessed as being with overweight and obesity; the overweight and obesity prevalence rate (17.69% and 14.89%) of the boy students were significantly higher than those (12.22% and 9.48%) of the girl students (χ² = 42.604 and χ² = 47.399; both P < 0.001). There were no significant differences in frequencies of having breakfast and meat consumption, and in the frequency and amount of legume and fruit among the students with different body weight (all P > 0.05); however, there was a statistically significant difference in the amount of meat consumed each time (χ² = 37.154, P < 0.001). The logistic regression analysis results showed that being male, consuming a high amount of meat each time, and having a high frequency of beverage consumption per week were common risk factors for overweight and obesity. Younger age, insufficient sleep, and consuming multiple types of vegetables per day were risk factors for obesity.

  Conclusion  The overweight and obesity were prevalent among primary and secondary school students in Zhejiang province, especially among young boys. Limiting total energy intake, consuming moderate amounts of meat, reducing the frequency of beverage consumption, and ensuring adequate sleep should be promoted for controlling overweight and obesity among the students.