I have definitely noticed this in my own life; when I was living in the suburbs I was starting to put on weight. When I moved out and started taking the bus every day, I went back down to a more manageable level.
The research could have major implications for urban planning and public transit development, Lachapelle says.
"You don't necessarily have to rebuild communities or make major investments in infrastructure to promote public health," he says. "There are things we can do in the interim, such as encourage people to drive less, and adapt their lifestyles which will get people more physically active and generate fewer greenhouse gasses."