Fig. 8

Relationship between walkability and activity inequality holds within cities in the USA of similar income. We found that walkability was associated with lower levels of activity inequality. To help account for potential confounding due to socioeconomic factors, we grouped the 69 cities in our analysis into quartiles based on median household income (data from the 2015 American Community Survey⁷⁵). We found that walkable environments were associated with lower levels of activity inequality for all four groups (LOESS fit). The effect appears to be attenuated for cities in the lowest median household income quartile. These results suggest that our main result—activity inequality predicts obesity and is mediated by factors of the physical environment—is independent of potential socioeconomic bias in our sample. This figure is adapted from our previous work¹¹ and reproduced with permission