Bidirectional Mediating Effects between Problematic Internet Use and Obesity-Related Eating Behavior on College Students’ Sub-Health Status: A Cross-lagged Panel Analysis

Previous studies have primarily explored binary relationships between problematic internet use (PIU), obesity-related eating behavior (OEB), and sub-health status (SHS) using cross-sectional designs, leaving gaps in understanding their dynamic interactions and developmental trajectories. Using two-wave longitudinal data (2022 & 2024) from 3,609 Chinese college students, this study employed cross-lagged panel model to examine bidirectional relationships between PIU and OEB, and half-longitudinal mediation models to explore their underlying mechanisms affecting SHS. The findings revealed that OEB significantly predicted subsequent PIU, while PIU showed no significant delayed effect on OEB. Half-longitudinal mediation analysis demonstrated that PIU contributed to SHS through its immediate positive effect on concurrent OEB, while OEB increased SHS through its positive effect on subsequent PIU. This study reveals the complex temporal dynamics between PIU and OEB, demonstrating a negative spiral pattern where these behaviors mutually reinforce each other, and highlighting their synergistic effects on college students’ SHS through bidirectional mediating pathways. These findings suggest that preventing and improving SHS requires simultaneous intervention in both PIU and OEB rather than treating them as isolated issues.