The Distribution of Physical Activity in an After-school Friendship Network

Abstract

WHAT'S KNOWN ON THIS SUBJECT: New, effective approaches to obesity prevention are urgently needed. Social network interventions warrant our attention. Social networks play a significant role in adult and adolescent obesity. The role of social networks in pediatric obesity has not been examined. WHAT THIS STUDY ADDS:Afterschool friendship ties play a critical role in setting physical activity patterns in children as young as 5 to 12 years. Children' s activity levels can be changed by the activity level of their social network during a 12-week afterschool program. abstract OBJECTIVE: To examine whether a child' s friendship network in an afterschool program influences his/her physical activity.METHODS: Three waves of data were collected from school-aged children participating in aftercare (n = 81; mean [SD] age, 7.96 [1.74] years; 40% African American, 39% white, and 19% Latino) a name generator survey was used to map each child' s social network, and accelerometers were used to measure physical activity. We applied stochastic actor-based modeling for social networks and behavior.RESULTS: Children did not form or dissolve friendships based on physical activity levels, but existing friendships heavily influenced children' s level of physical activity. The strongest influence on the amount of time children spent in moderate-to-vigorous activity in the afterschool hours was the activity level of their immediate friends. Children consistently made adjustments to their activity levels of 10% or more to emulate the activity levels of their peers (odds ratio [OR] = 6.89, P , .01). Age (OR = 0.92, P , .10) and obesity status (OR = 0.66, P , .10) had marginally significant and relatively small direct effects on the activity. Gender had no direct effect on activity. CONCLUSIONS:These results suggest that friendship ties play a critical role in setting physical activity patterns in children as young as 5 to 12 years. Children' s activity levels can be increased, decreased, or stabilized depending on the activity level of their immediate social network during a 12-week afterschool program. Network-based interventions hold the potential to produce clinically significant changes to children' s physical activity.