Growth, nutritional status, and physical fitness trajectories among primary and secondary school students and their associations with poor vision: a school-based study in Chongqing, China.

Abstract

Purpose: To examine trends in growth and development, physical fitness, and visual acuity indicators among primary and secondary school students in Yuzhong District, Chongqing, and to explore the associations of body mass index (BMI) and vital capacity index (VCI) with poor vision.

Methods: Physical examination data of primary and secondary school students in Yuzhong District, Chongqing, from 2022 to 2026 were used to describe growth and development, physical fitness, and visual acuity indicators. Group-based trajectory modeling (GBTM) was applied to identify distinct trajectories of BMI and VCI. Logistic regression was used to analyze the associations between BMI and VCI trajectories and the detection rate of poor vision, as well as potential nonlinear relationships.

Results: From 2022 to 2026, height, weight, and VCI increased among primary and secondary school students in Yuzhong District, Chongqing, while obesity prevalence declined (all trend p < 0.001). Poor vision increased from 73.3 to 75.0%. GBTM identified three trajectories for BMI and four trajectories for VCI. Compared with the low-level increasing BMI trajectory, medium and high-level increasing trajectories were associated with 13.4 and 36.8% higher odds of poor vision, respectively. For VCI, the medium-level decreasing trajectory was associated with 11.7% higher odds, whereas the high-level decreasing trajectory was associated with a 37.1% lower risk.

Conclusion: From 2022 to 2026, growth and development indicators among primary and secondary school students in Yuzhong District improved, while poor vision remained prevalent. BMI and VCI trajectories were associated with poor vision, highlighting the importance of integrated monitoring and targeted interventions.