Connections between Friendship Quality, Peer Competence, and Obesity in Early Childhood through Adolescence.

Background: Research indicates that youths with overweight and obesity often face difficulties in peer relationships. The current research examined longitudinal associations between youths' peer competence ( i.e. , successful interactions with peers), friendship quality ( i.e. , disclosure, conflict resolution, and companionship with a best friend), and body mass index (BMI) z-score when they were 3 to 15 years of age. Methods: A subsample of 1292 majority White families from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD) were included in the analyses. Measured height and weight were used to compute BMI z-scores. Youths reported on their friendship quality starting when they were 8-9 years. Peer competence was assessed with an observation of dyadic peer play when participants were 3 years old, and with maternal reports after that. Associations were examined using autoregressive cross-lagged path models. Results: Bidirectional associations between peer competence and friendship quality were noted when participants were 8-9 and 15 years old. Greater BMI z-scores when youths were 3 and 10-11 years old predicted lower peer competence when they were 15 and 11-12 years old, respectively. Peer competence when youths were 11-12 years old was negatively associated with BMI z-score at 15 years old. Multigroup Structural Equation Modeling (SEM) indicated that significant paths differed between boys and girls. Conclusions: Findings extend previous literature considering peer outcomes and weight by examining associations as early as 3 years old, and indicate the need for early outreach to buffer against detrimental effects on developing peer competencies, especially for girls.