Background: African American (AA) and Hispanic children are at high risk of developing obesity. Social networks are powerful drivers of health behaviors and outcomes. Parent social network characteristics may influence child health behaviors and obesity risk.

Methods: This is a cross-sectional, observational study of parents of AA and Hispanic children 2-4 years. The social network survey was adapted from The Important and Health Matters Social Network Battery (PhenX Toolkit). Child health behavior questions were from the National Health and Nutrition Examination Survey. Child body mass index z-score (BMIz) was calculated based on measured height and weight at the child's most recent well-child visit. Linear regression models identified associations between parent network characteristics, BMIz, and child health behaviors. Participants included 44 parents of Hispanic children and 74 parents of AA children.

Results: Parents of Hispanic children named fewer supportive alters (network members) than parents of AA children (3.7 vs. 5.0, p < 0.1). A higher number of stressful parent relationships was associated with higher child BMIz (β = 0.2, p < 0.05). For parents of AA children, a higher number of supportive alters was associated with more hours of child weekday (β = 0.2) and weekend sleep (β = 0.2) and less child weekday screen time (β = -0.2) (all p < 0.05). For parents of Hispanic children, a higher number of alters with whom the parent discusses important matters was associated with more hours of child weekday sleep (β = 0.3, p < 0.05).

Conclusions: Parent social network characteristics are population-specific and associated with child health behaviors and BMIz. Augmenting supportive parent relationships and stress coping may reduce child obesity risk.