Exploring the associations between active school transport, child obesity, and child poverty in California

Background: Over the last few decades, rates of active transport (AST) among school age children have decreased as rates of child obesity have increased. Thus, it has been proposed that increasing AST in this population would help stem the tide of child obesity and improve child health. The evidence for the capacity of AST to reduce child obesity, however, is mixed. Purpose: To examine the association between AST and child obesity among California schoolage children and further investigate alternative explanations for the aforementioned mixed evidence. Methods: Spearman’s correlation analyses were conducted in 2012 using AST data obtained from public elementary schools participating in the California Safe Routes to Schools program in 2010 (n=168), along with child health measures inversely related to child obesity, i.e., Body Composition (BC) and Aerobic Capacity (AC), extrapolated from the 2010-11 California Physical Fitness Test required by the State, and administered annually to students. The use of coded private information did not meet the definition of a human subject and did not require IRB review. Results: A negative and weak but significant association emerged between AST and BC (rs = -0.189, p=0.0014), indicating that AST rates increased, child obesity rates increased as well. A similar association emerged between AST and AC, but it was not statistically significant. A weak but significant association emerged between AST and child poverty (rs = 0.252, p=0.0017), indicating that as AST rates were higher among poor children. Strong and very significant associations emerged between child poverty and both AC (rs = -0.751, p<.0001) and BC (rs = -0.826, p<.0001), indicating that poor children had significantly worse health and higher weight. Conclusion: This study provides support for the scarce studies that have found that higher rates of AST are associated with higher rates of child obesity. It also replicates studies showing greater AST participation among poor children, and suggests that poverty may explain both higher obesity and higher AST rates among poor children, thus the observed, counterintuitive association between the latter. These results warn against child obesity policies that focus unduly on behavioral/environmental interventions yet neglect the role of the social determinants of child health. Further exploring how socioeconomic status interacts with health behaviors could help better understand the relationship between AST and child health and inform more effective public health policies.