A while back I theorized (with chart) about the varying weights of urban, suburban and rural citizens. Bree has linked to a study that verifies my theories:
Americans who live in the most sprawling counties tend to weigh 6 more pounds than their counterparts in the most compact areas. Adding to the sprawl concern: Pedestrians and bicyclists are much more likely to be killed by passing cars here than in parts of Europe where cities are engineered to encourage physical activity - and whose residents typically are skinnier and live longer than the average American.
She also has some interesting thoughts on growing up in the suburbs.