Singleton status and childhood obesity: Investigating effects and mechanisms Status :

Over the past four decades, paralleling the increasing prevalence of childhood obesity, the share of families with only one child has been rising steadily. Using three waves of the National Survey of Children's Health, we examine the effect of being the only child in a family on childhood obesity and the mechanisms through which singleton status might affect childhood obesity. We find gender-specific and age-dependent singleton effects. That is, singletons have a higher level of body mass index and a higher obesity rate than children with siblings. The singleton effects are more pronounced for younger cohorts aged 10-13 than older cohorts aged 14-17 and for males than females. We also find that singletons exercise less, are less likely to participate in after-school sports teams or take sports lessons, and spend more time watching television/video and playing video/computer games. The findings not only suggest a potential target — singletons — for childhood obesity prevention and interventions, but also highlight the importance of coordinating policies on childhood obesity and fertility.