We shouldn't be surprised--the tenuous link between low density living and obesity is driving special interest calls for more public spending. In this case, Houston's Quality of LIfe Coalition is lobbying for more money for parks, bike trails, and walking trails to combat its recent ranking as one of the nation's fattest cities. A recent Houston Chronicle story notes that the coalition "was instrumental in persuading [the city of Houston] to invest an additional $58 million in the city's off-road bike-trail program in the next two years.
Interestingly, the article spends a lot of time talking about recent studies linking sprawl to obesity, but presents no evidence that more bike trails or parks will increase physical activity or reduce obesity. In fact, there is virtually no critique of the studies at all. (For that, Reason has a lot of material, including my essay on the topic.)