Rich and Poor in Opportunities to Walk

Here’s a fascinating new way to look at health disparities. How much disparity does a place have in walking? Does everyone take many steps per day? Or do some take a lot while others take very few? A new study in Nature finds that disparities in opportunities to walk predict higher obesity rates.

 Big Data from Smartphones

Tim Altoff and colleagues from Stanford obtained data from 717,523 people through motion sensors in their smartphones. This massive dataset describes 68 million days of physical activity in 111 different countries.

The researchers matched the data to obesity rates and to data on walkability of different cities represented.

Activity Disparities Predict Obesity

Altoff et al found that activity inequality – where some people walk a lot, while others walk very little – predicts obesity better than average activity levels. Women account for the biggest disparities. In places where everyone gets plenty of walking, it’s because more women are walking.

More Walkable Cities Have Less Disparity

These data also suggest that more walkable cities might be leading to more people walking and thus, to less disparity in physical activity. More women walk more when the built environment makes it easier.

Interestingly, these data emerge at the same time as new CDC data on self-reported walking. In self-reports, women seem to be walking more than men. But the objective data from smartphones tell a different story. Maybe women are better informed about what they should be reporting.

In any event, these data give us much to think about. Are we addressing the health needs of many or few? Is physical activity available to all? Are we doing enough to make our communities more walkable?

Health disparities have many dimensions. Access to care is clearly an issue. Economic and social disparities clearly have a harmful impact on health. And now we have one more dimension to consider – access to a healthy, walkable environment.

Click here for the study in Nature and here for further perspective from Futurity.

Evening Walk, watercolor by Martiros Sarian / WikiArt

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July 13, 2017