Peer effects on sugar-sweetened beverage consumption among children and adolescents: evidence from rural Western China.

INTRODUCTION: Excessive sugar-sweetened beverage (SSB) consumption among children and adolescents in rural areas has become an important public health concern. Although peer influence on adolescent health behaviors has been widely recognized, the mechanisms linking peer SSB consumption to individual intake remain insufficiently understood, particularly in rural settings characterized by boarding education and limited parental supervision. This study examined the association between peer and individual SSB consumption among rural students and explored the mediating role of nutritional cognition. METHODS: Cross-sectional survey data were collected from 1,901 students in 25 primary schools and 11 junior high schools in the Jining District of Ulanqab City, Inner Mongolia, China. Ordinary Least Squares (OLS), Instrumental Variable (IV), and Generalized Propensity Score Matching (GPSM) models were employed to estimate the association and assess the robustness of the findings. Mediation analysis was conducted to examine the role of nutritional cognition, and heterogeneity analyses were performed by boarding status and parental cohabitation. RESULTS: Peer SSB consumption was positively and significantly associated with individual SSB consumption (β = 0.918, p < 0.001). Nutritional cognition partially mediated this association. Heterogeneity analyses indicated that the positive association was stronger among boarding students and those not living with their parents than among non-boarding students and those living with their parents. DISCUSSION: The findings suggest that peer behavior is an important correlate of individual SSB consumption among rural students, partly through its association with nutritional cognition. The stronger association observed among boarding students and those without parental cohabitation highlights the increasing importance of peer influence when parental supervision is limited. These findings support the development of school-based interventions that strengthen positive peer norms and nutrition education to reduce SSB consumption among rural youth, particularly in boarding school settings.