A new case study coming out of Switzerland suggests that a city’s urban layout may be the greatest factor in rate of obesity amongst its residents. Published in the British Medical Journal Open, the study calculated the BMIs (body mass index) of 6,500 adult residents for many years in the city of Lausanne, Switzerland, and then used demographic information to map the BMIs. What they found was a stark divide between the working-class, less-educated residents clustered in the city’s western edge—who had higher BMIs—and the wealthier, well-educated residents farther east with proportionally lower BMIs. The findings showed that these low-income neighborhoods lying in the midst of large roads, crowded highways and metro lines isolated working-class communities from “places that could be very healthy for them” such as parks and green spaces, areas far more accessible for the wealthier residents of the city. The study’s results may have found the missing link between urbanism and obesity, signifying that reducing obesity rates will require improvements to our urban environments.