Active Transport is Associated with Lower BMI in Adults with Low Levels of Non-Active-Transport-Related Physical Activity

Background: Most US adults do not achieve the recommended target of 150 minutes/week of moderate physical activity (PA). New strategies to help individuals obtain sufficient PA are urgently needed. Active transport (biking and walking for transportation) incorporates PA into individuals' existing daily routines. However, it is unclear if active transport confers the same health benefits as other forms of PA. Thus, we sought to examine the relationship between active transport and body-mass index (BMI) among adults not meeting PA recommendations. Methods: Using self-reported data from NHANES 2007-2008, we categorized adults aged 20-79 (N=2,397) according to level of active transport per week: none (80.7%), 1-59 min (2.9%), 60-119 min (4.8%), and 120+ min (11.6%). We evaluated the association between active transport and BMI using multivariable linear regression with adjustment for sociodemographic characteristics, diet quality, smoking status, and minutes/week of non-transport-related PA. Results: Overall, there was a significant inverse association between level of active transport and BMI, with mean BMI ranging from 30.1±7.3 kg/m² among those engaged in 0 min/week of active transport to 28.6±6.3 kg/m2 among those engaged in 120+ min/week of active transport (p=0.014). After adjusting for covariates, individuals in the highest level of active transport continued to have a 0.9 kg/m² lower mean BMI than those who engaged in no active transport (p=0.04). Conclusion: Active transport is associated with lower BMI in adults not meeting PA recommendations through recreational and work-related physical activity. Efforts should be made to develop policies and infrastructure that promote the use of active transport.