Place and public health, part 2: Proximity to restaurants vs. mass transit for weight loss
In public health, place matters. And researchers from the University of Buffalo have underscored this assertion with a new study this week that begins to untangle the interaction of the built environment, food environment, and risk of being overweight (as measured by body mass index, or BMI: Higher BMI means you're more likely to be overweight or obese, lower BMI means being thinner). Public health researchers have long held that more walkable neighborhoods are likely to be healthier, not only because they promote physical activity but also because inviting people to walk around the block also sparks social interaction that build a sense of community. But this new research throws a slight kink in that line of reasoning, suggesting that its not just walking, but what folks can walk to that makes a difference.
Published in the Journal of Planning Education and Research, this pilot study of 172 women had three potentially significant findings:
1. The more restaurants there are within a five-minute walk of a person’s home, the greater their BMI (and therefore the more likely they are to be overweight.)
2. Living closer to supermarkets or grocery stores, as compared to convenience stores, is associated with lower BMI.
3. Urban environments that promote walking also promote higher BMI’s, and hence being overweight, when the landscape is filled with restaurants.
This research is interesting on several levels. It shows that just getting people to walk more may not be a panacea that prevents obesity and overweight, instead you have to consider the food environment that they are walking into. Public health research has found that folks living in neighborhoods that lack access to healthy foods tend to have poorer diets, and are more likely to be larger. And often those neighborhoods do not welcome outdoor activity. But here we see that overburdening even the most walkable neighborhood with fattening food choices may lead to folks being active yet overweight, while providing convenient access to high quality food options may promote healthy slimness.
Meanwhile, the August issue of American Journal of Preventive Medicine unearths the weight loss potential of another piece of the built environment: mass transit. Using a new light rail transit (LRT) commuter line in Charlotte, North Carolina for 12-18 months was associated with the equivalent of a 6.5 pound weight loss in a person 5’5’’ tall, compared to non-LRT users. In fact, LRT users were 81% less likely to become obese over time, compared to those who commuted using other means. Unlike car drivers, users of mass transit spend time walking to and from stations, and standing while waiting for a bus or train, which they may stand on while riding. All of these things burn calories and build muscles necessary for maintaining healthy weight.
As is typical of public health interventions, effective approaches to promoting health require multi-disciplinary, multi-faceted approaches.
Part one of this series looked at social characteristics of neighborhoods linked with developing childhood obesity.