B.U. will soon be publishing a paper showing that on a sprawl index from 1 to 100, the risk of obesity goes up about a quarter of a percentage point for each 1 point increase in a region's rating, Boston University research assistant professor Russ Lopez said this morning. (To give you an idea of how the index works, New York City is rated 5 while Atlanta is a 90).
Local factors also make a difference. In a study of eastern Massachusetts "from Worcester to the ocean," he said, the built environment from zip code to zip code makes a difference - even controlling for other factors such as age and education.
If there's a supermarket in your zip code, for example, you're 20% less likely to be obese. If there are a lot of intersections in your neighborhood - a sign of street connectivity and continuity - you're less likely to be obese. And, not surprisingly, the more time people spend in their cars, the more likely they are to be obese.
One of his most interesting points came during the question and answer period, when he made this intriguing remark: Homes and neighborhoods built before 1975 tend to be substantially more walkable than those built afterwards. "That's when we went over the cliff," he said - he's not sure why - and tilted overwhelmingly toward auto-centric planning at the expense of walkable communities.
Basically, there are two types of solutions for the health, environmental and safety problems generated by our heavily auto-dependent society: "narrow" and "broad." "Narrow" ones look to mitigate specific problems - cleaner and more efficient engines to help with emissions, safer vehicles and roadways to try to ease traffic fatalities (which are the number-one cause of death for Americans ages 3 to 33) and so on.
They're important, but they're not enough.
If we ever hope to make progress on these issues, especially the health-related ones, we also need to look at the broad solutions that will restore some balance between the needs of pedestrians and drivers.
That means zoning to allow pedestrian-friendly streetscapes -- buildings up at the street, mixed-use residential and commercial area and so on.
Zoning originally had good intentions: protecting people from living near dangerous and unhealthy industries. But, said Lopez, "We've gone too far." Current Boston zoning wouldn't allow some of the city's most desirable and attractive neighborhoods to be rebuilt as they are today - neighborhoods like the South End and Back Bay, where people can easily walk to stores and restaurants, he noted. And that's the same in communities across America.
It also means lessening the public financing of our automobile-dependent lifestyle. Some whine endlessly about public funding of mass transit, but don't seem to realize that gasoline taxes only pay for about one-third of our road building and maintenance costs. "We subsidize cars in this country," he said.
And, we design for them. "When you make it so people can't even go to the gym without driving..."