[Association between diet-exercise patterns and central obesity in students in China]

Objective: To investigate the association between diet-exercise patterns and central obesity in primary and secondary school students in China. Methods: The data from the 2023 "Nutrition Improvement Program for Students Compulsory Educationin Rural Area" Nutritional Health Monitoring, which was conducted in 121 912 students aged 8-15 years in primary and secondary schools (grade 3-9) in 115 counties in China. Standardized procudures were used to measure students' fasting height, weight, and waist circumference in the morning. The information about dietary intake and physical activity levels of the students were collected by using questionnaires. Latent class analysis was conducted based on the selection of variables with strong associations to extract students' diet-exercise patterns. The associations between diet-exercise patterns and central obesity were examined with both binary logistic regression and generalized ordered logistic regression models. Results: The prevalence of central obesity was 16.6% in students with normal waist circumference and 17.2% in students with high waist circumference when defined by waist circumference, while 20.6% when defined by waist-to-height ratio (WHtR). Five distinct diet-exercise patterns were identified: low food intake & low activity, frequent beverage/fried food intakes & high activity, infrequent beverage/fried food intakes & high activity, frequent beverage/fried food intakes & low activity, and infrequent beverage/fried food intakes & low activity. After adjusting for confounding factors, both logistic regression models consistently showed that frequent beverage/fried food intakes & high activity pattern was positively associated with central obesity risk compared with infrequent beverage/fried food intakes & high activity pattern (OR=1.142, 95%CI: 1.095-1.192; OR=1.125, 95%CI: 1.075-1.177). The low food intake & low activity pattern was negatively associated with central obesity risk (OR=0.889, 95%CI: 0.849-0.931; OR=0.865, 95%CI: 0.824-0.909). Additionally, high meat intake and daily frequent food intake patterns were negatively associated with central obesity risk (both P<0.001). Conclusions: Regular food intake and high meat intake patterns showed negative associations with central obesity. The frequent beverage/fried food intakes & low activity patterns were positively associated with central obesity risk in primary and secondary school students in rural area in China. It is suggested to conduct interventions, such as nutritional health education, with emphasis on post-exercise dietary choice to reduce central obesity risk in this population.