Influencing Factors of Disordered Eating Behavior Among Chinese University Students: The Moderating Role of Physical Activity in the Body Status Chain Mediation Model

Purpose: To explore the impact and mechanism of weight status on the disordered eating behavior of university students, this study conducted a moderated chain mediation model based on the Escape Theory and the Strength Model of Self-Control. Methods: This was a cross-sectional online study conducted at a university in Shanghai. The questionnaire was distributed via communication tools such as WeChat from March 6 to 15, 2022, receiving 2618 valid responses. The moderated chain mediation model was empirically examined with 10,000 Bootstrap samples using AMOS software. Results: (1) Weight status can indirectly predict disordered eating behavior through the mediating effect of body dissatisfaction (β = 0.24, 95% CI: 0.22–0.26, p < 0.001); (2) Body dissatisfaction and negative affect play a chain mediation role in the positive impact of weight status on disordered eating behavior (β = 0.01, 95% CI: 0.01–0.02, p < 0.001); (3) Physical activity moderates the positive impact of negative affect on disordered eating behavior (Diff = −0.11, t = 2.20, p < 0.05) and further plays a moderating role in the chain mediation model (Diff = −0.01, t = 2.30, p < 0.05). Specifically, the higher the level of physical activity among university students, the weaker the impact of negative affect on disordered eating behavior, and the weaker the chain mediation effect; (4) The level of physical activity moderates the relationship between weight status, body dissatisfaction, and disordered eating, suggesting that the higher the level of physical activity, the stronger the mediating role of body dissatisfaction between weight status and abnormal eating (Diff = 0.12, t = 2.74, p < 0.05). Conclusion: These findings revealed the pathways through which weight status affects the eating behavior of university students and how physical activity might weaken or strengthen this impact. This research supplements prior studies and offers insight into health promotion for university students.