The role of distance in examining the association between active commuting to school and students' weight status

Background: Active commuting to school (ACS) increases students' daily physical activity, but associations between student weight and ACS are inconsistent. Few studies examining ACS and weight account for distance commuted. This study examines the association between students' weight status and ACS, taking into account distance to school. Methods: In 2009-10 a random digit-dial household survey conducted in low-income minority cities collected information about ACS for 1 randomly selected school-going student per household. Parents provided measured heights and weights. Distance commuted was obtained using geocoded home and school addresses. Multivariate regression analyses assessed associations of ACS and distance commuted with weight status. Results: 36.6% of students were overweight/obese; 47.2% engaged in ACS. Distance walked/biked to school was associated with 7% lower odds of overweight/obesity (OR = 0.93, 95% CI: 0.88- 0.99). Without distance commuted in the model, ACS was not associated with students' weight status. Compared with no ACS, ACS greater than a half-mile was associated with 65% lower odds of a student being overweight/obese (OR = 0.35, 95% CI: 0.16- 0.78); ACS less than a half-mile was not. Conclusions: ACS is significantly inversely associated with overweight/obesity among students who commute beyond a one-half mile threshold.