Despite a firm reputation for being walkers, New Yorkers have an obesity epidemic on their hands. Lee Altman, a former employee of New York City’s Department of Design and Construction, explains it this way: “We did a very good job at designing physical activity out of our daily lives.”

According to the city’s health department, more than half of the city’s adult population is either overweight (34 percent) or obese (22 percent), and the convenience of their environment has contributed to this. “Everything is dependent on a car, elevator; you sit in front of a computer,” said Altman, “not moving around a lot.”

This is not just a New York phenomenon. Mass urbanization has caused populations the world over to reduce the amount of time they spend moving their bodies. But the root of the problem runs deep in a city’s infrastructure.

Safety, graffiti, proximity to a park, and even the appeal of stairwells all play roles in whether someone chooses to be active or not. But only recently have urban developers begun giving enough priority to these factors.