I tend to agree with those who think that solely banning fast-food chains in poor neighborhoods isn't likely to help increase the # of "healthy" restaurants and grocery stores. First, sit-down restaurants have more expensive meals, and as others have said, they are not necessarily much healthier than fast food -- especially the large-portion chains.

What's needed are more supermarkets. The city government, maybe in conjunction with state/federal government, should be able to set up "healthy enterprise zones" in which appropriate businesses would get tax incentives or even subsidization to put in grocery stores, big and small -- one could include in this restaurants with healthy, low cost menus. The city could also set up and subsidize farmers markets for these parts of town.

Also, more nutrition education needs to be offered in the schools and to adults -- particularly in poorer neighborhoods.

Just keeping fast food joints and liquor out of such neighborhoods, alone, is not going to solve the problem.

As an aside, the trans fat proscription is a sensible and righteous act. Trans fats are just plain bad for everyone's arteries, and there are plenty of viable substitutes for these nasty fats.