Levittown and Veal Pens

Modern neighborhoods are to veal pens as pre-1950 neighborhoods are to free-range farms.

According to a study from the University of Utah, residents of older neighborhoods are slimmer. The body mass index of nearly half a million people, linked to 2000 census data, shows that larger people live in newer housing developments. The researchers think that it has to do with "walkable neighborhoods."

Neighborhoods built before 1950 offered more opportunities to walk, were more densely populated, and had a larger range of pedestrian destinations. The newer neighborhoods, which are geared towards car travel, actively discourage walking.

I'm not sure how accurate that hypothesis is. Yes, the study shows a correlation between residents having a higher body mass and neighborhoods that were constructed more recently, but maybe skinny people who have good exercise habits are naturally drawn to neighborhoods that give them more opportunities to walk. Or maybe newer neighborhoods offer more opportunities to consume fructose.