The impact of peer effect on students' consumption of sugar-sweetened beverages- instrumental variable evidence from north China

Sugar intake is approaching problematic levels among Chinese children and adolescents. Chinese governments have issued and supervised the implementation of relevant administrative regulations, which have not achieved good results. Peers are the most important social factors influencing children and adolescents' behavior and decision-making besides family members. This study examines how the peer effect impacts SSB consumption. To clarify this relationship, we use the nutritional cognition of peers' parents as an instrumental variable to resolve the endogeneity problem and employ the two-stage least squares estimation method to investigate the data of 4,118 students in north China. The results show a significant positive correlation between sugar intake among peers, indicating that individuals are more likely to consume excessive amounts of sugar when their peers also engage in this behavior. We find that the peer effect is enhanced with increased popularity among one's peers and gradually decreases as the distance within the social network increases. It is also more significant in short-term friendships than in long-term friendships. Our findings provide a basis for school-level intervention programs from the perspective of social interaction to regulate healthy eating behaviors and nutritional perceptions among children and adolescents through peer relationships. It also confirms the feasibility of reducing individual sugar intake by increasing nutritional awareness among adolescents and parents.