摘要：Objectives. To determine whether 2012 to 2015 (times 1–3) ridership changes correlated with body mass index (BMI) changes after transit line completion in Salt Lake City, Utah. Methods. We used Global Positioning System/accelerometry–measured transit ridership measures in 2012 to 2013 (times 1–2) to compare objective and self-reported ridership. Regression models related changes in objectively measured ridership (times 1–2) and self-reported ridership (times 1–2 and times 1–3) to BMI changes, adjusting for control variables. Results. Objective and self-reported ridership measures were consistent. From time 1 to 2 ( P = .021) or to 3 ( P = .015), BMI increased among self-reported former riders and decreased among new riders ( P = .09 for both times 1–2 and times 1–3), although the latter was nonsignificant. Time 3 attrition adjustment had no effect on results. Adjusting for baseline BMI, the nonsignificant effect for new riders remained nonsignificant, indicating no BMI change; the BMI increase after discontinuing transit remained significant. Conclusions. Observed BMI increases subsequent to stopping transit ridership persisted for more than 2 years (postintervention). These results suggest that transit ridership protects against BMI gains and support the need to provide convenient transit for public health. Complete street renovations, which provide new infrastructure for active travel via transit, walking, or biking, might support greater physical activity, which may help prevent weight gain. Such infrastructure improvements likely support more physical activity, 1 but few studies include objectively measured body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) over time. 2 In 2 self-report studies, US adults who started riding new light-rail service lost weight 3 ; UK adults who stopped riding transit gained weight. 4 In light of these findings, we assessed a complete street intervention involving new rail, sidewalks, and bicycle lanes in Salt Lake City, Utah. Our previous publication, from preconstruction and postconstruction data (2012–2013), showed that BMI was related to Global Positioning System (GPS)/accelerometry–measured transit ridership. 5 New riders lost BMI, and former riders gained BMI, 1 to 7 months after construction. 5 Over time, adults often gain weight 6 and infrequently sustain weight loss. 7 We used 2012 to 2013 data to establish reliability of self-reported transit ridership and then examined whether self-reported ridership change was related to longer-term BMI change 25 to 32 months after construction (2015).
