Physical activity and fruit and vegetable intake among Chinese college students through psychological pathways

Regular physical activity and a balanced diet are key modifiable lifestyle factors essential for maintaining good health. Existing studies indicate that fewer than 40% of Chinese college students meet the recommended daily standards for physical activity and fruit and vegetable intake. The "exercise-nutrition synergy" paradigm has been incorporated into disease prevention and control strategies, aiming to enhance undergraduates' physical and mental health through the simultaneous promotion of health-related behaviors and nutritional guidance. Therefore, this study aimed to examine the relationship between physical activity and fruit and vegetable intake among college students and to explore the mediating roles of self-esteem and depressive symptoms, thereby providing evidence-based insights for reducing psychological disorders and promoting healthy behaviors in this population. A convenience sampling method was used to recruit 3,989 college students (mean age = 19.04 ± 1.15 years) from Hunan, Shaanxi, Yunnan, Sichuan, and Shandong provinces. A questionnaire survey was administered to collect basic demographic information and assess levels of physical activity, self-esteem, depressive symptoms, and fruit and vegetable intake. The PROCESS macro for SPSS 26.0 was employed to test the proposed cross-sectional chain mediation model. Physical activity was positively correlated with self-esteem (r = .081) and fruit and vegetable intake (r = .230), and negatively correlated with depressive symptoms (r = - .058). Self-esteem was positively associated with fruit and vegetable intake (r = .135) and negatively associated with depressive symptoms (r = - .198). Fruit and vegetable intake was negatively correlated with depressive symptoms (r = - .145). Mediation analyses showed that physical activity was positively associated with self-esteem (β = 0.086) and negatively associated with depressive symptoms (β = -0.034), while self-esteem was also negatively associated with depressive symptoms (β = -0.198). Both physical activity (β = 0.239) and self-esteem (β = 0.092) were positively associated with fruit and vegetable intake, whereas depressive symptoms were negatively associated with fruit and vegetable intake (β = -0.111; all p < .05). The direct association between physical activity and fruit and vegetable intake was β = 0.238 (Bootstrap 95% CI 0.208 to 0.268). Indirect associations were observed through self-esteem (β = 0.008, Bootstrap 95% CI 0.004 to 0.012) and depressive symptoms (β = 0.004, Bootstrap 95% CI 0.000 to 0.008). The sequential indirect association through self-esteem and depressive symptoms was also significant (β = 0.002, Bootstrap 95% CI 0.001 to 0.003). Self-esteem, depressive symptoms, and their sequential indirect pathway were statistically involved in the association between physical activity and fruit and vegetable intake among college students. Because the study was cross-sectional, these findings should be interpreted as indirect associations rather than causal effects. Health promotion programs for college students may benefit from integrating physical activity, positive self-evaluation, emotional well-being, and dietary guidance.