The Role of Active Transportation to School on Childhood Obesity Prevention in China

With the growing trend of childhood obesity, active transporting (e.g. walking or bicycling) to and from school (ATS) has been recommended as an important source of daily physical activity and obesity prevention among schoolchildren in the U.S. and Europe. In China, childhood obesity has steadily increased over the past decades, and ATS can be a potential solution to prevent further increase of childhood obesity. However, there is little evidence on effectiveness of ATS on reducing childhood obesity. This study contributes to the literature by examining whether ATS reduces obesity and overweight among Chinese schoolchildren and how the effect of ATS is moderated by the built environmental factors and school locations.

We use the 1997-2009 China Health and Nutrition Surveys Data, and derive an analytic sample of 2,187 children (5,164 individual-wave observations) aged between 6-18. Our weight outcome measures include continuous standardized body mass index (BMI) and two dichotomous variables indicating whether a child is overweight or obese. We use ordinary least square (OLS) technique to examine whether there is any significant effect of ATS on childhood obesity, when controlling for household characteristics, intensity of other non-ATS physical activity, and community urbanization indices. We also use the changes in the availability of schools within the community to investigate how the relationship between ATS and obesity is moderated by school locations. We utilize the longitudinal nature of the data and include the individual fixed effects, in order to control for the time invariant individual characteristics.

Our results suggest that the ATS alone did not have a significantly independent effect on reducing obesity, but there is a strong interaction effect of ATS time and school location on the likelihood of childhood overweight and obesity. More specifically, the incidences of being obese and overweight for children whose schools were located within their own communities would decrease by 1.4% and 2.4%, if they spend at least 15 minutes per day on ATS. The magnitudes of these estimates were smaller and less precisely estimated when the fixed effects methods were not applied. However, the results for children whose schools are outside their own communities are not significant. Our findings indicate that the ATS has heterogeneous effects on schoolchildren. For children who attend local schools within communities, the ATS could be an effective way of reducing obesity and overweight; for children travelling outside of their communities for education, future interventions other than ATS are necessary to address the obesity issue.