Abstract
BACKGROUND: Unhealthy weight control behaviors (UWCBs) are widespread in adolescents and have devastating consequences. Friendship network is potentially an important influence on university students' UWCBs. This study employs social network analysis to investigate the homophily of UWCBs among university students within peer networks and gender differences. METHODS: A longitudinal study comprising two data collection waves was conducted on 612 undergraduate students from five schools at two universities in Guangdong Province, China, forming five sociometric networks. UWCBs, incorrect self-perception of obesity, depression, and anxiety were measured using standard scales. Descriptive statistics, assortativity tests and network autocorrelation models were utilized for data analysis. RESULTS: Study recruited 214 (34.8%) males and 398 (65.2%) females, with the UWCBs prevalence of 28.6% (T0) and 30.0% (T1). A significant homophily of UWCBs enhancing with time was identified (ρ(T0) = 0.255, p = 0.046; ρ(T1) = 0.394, p = 0.020). Females (β = 0.185, p = 0.027), overweight (β = 0.673, p < 0.001), obesity (β = 0.499, p < 0.001), incorrect self-perception of obesity (β = 0.538, p < 0.001), depression (β = 0.264, p = 0.025) and lower network transitivity (β = -0.375, p = 0.048) were associated with higher level of UWCBs. Additionally, significant homophily in UWCBs was found among females (ρ(T0) = 0.340, p = 0.035; ρ(T1) = 0.412, p = 0.026) but not males (ρ(T0) = -0.031, p = 0.178; ρ(T1) = -0.065, p = 0.551). Significant gender differences were also observed in others risk factors of UWCBs. CONCLUSIONS: Our study found significant homophily and gender differences in UWCBs among first-year university students. These findings highlight the importance of considering peer networks and gender in future interventions.