Moderating effects of Walk Score® on the association between neighbourhood disadvantage and body mass index among mid-to-older aged Australian adults

This study examined whether the association between neighbourhood disadvantage and body mass index (BMI) was moderated by neighbourhood walkability among mid-to-older aged adults. Data were from the 2016 wave of the How Areas in Brisbane Influence Health and Activity (HABITAT) study, including 3249 mid-to-older aged adults residing in 200 neighbourhoods. Self-reported height and weight were used to calculate BMI; neighbourhood disadvantage was assessed using a census-derived index, analysed in quintiles; and walkability was determined using Walk Score®. BMI was associated with neighbourhood disadvantage with those residing in the most disadvantaged neighbourhoods (Q4 and Q5) having higher BMI compared to those in the least disadvantaged neighbourhoods (Q1). There was evidence of moderation by Walk Score in the most disadvantaged neighbourhoods (Q5). For every 10-unit increase in Walk Score, BMI differences between the most disadvantage neighbourhoods (Q5) and the least disadvantaged (Q1) reduced (β = −0.40, 95 % CI: −0.75, −0.05). These findings suggest that greater walkability in disadvantaged neighbourhoods may present an opportunity to narrow the health inequities observed across neighbourhoods. Improving walking infrastructure in disadvantaged neighbourhoods could promote physical activity and support healthier weight outcomes to reduce health disparities. • Greater neighbourhood disadvantage was associated with higher BMI. • Walk Score was lowest in the least disadvantaged neighbourhoods in Brisbane, Australia. • Walk Score moderated the association between neighbourhood disadvantage and BMI in the most disadvantaged neighbourhoods.