James Hamblin writes in the Atlantic about a new study, Community design, street networks, and public health, which looks at streets- their density, connectivity and configuration, and their effect on peoples' health. Not surprisingly, they found:
...cities with more compact street networks—specifically, increased intersection density—have lower levels of obesity, diabetes, high blood pressure, and heart disease. The more intersections, the healthier the humans.
The study also found a correlation between the number of lanes on a street with high rates of with high rates of obesity and diabetes, which is another great reason to convert some of them to bike lanes.
Wesley Marshall, co-author of the study, tells Hamblin: "The obesity epidemic is becoming a national crisis, but almost nobody connects that with neighborhood design." I don't think that's true; people have been talking about this for years. Here are a few posts making the connection between urban form, obesity and health:
Culs de Sac and 11 Other Unexpected Things That Are Making You Fat