Should food stamps be used for fast food?

How much further could food stamps go in providing food if people had to use them at grocery stores to buy basic food? If you buy already prepared food, you pay more. Should taxpayers pay to have the food prepared or just to provide the food? It is amusing that Democrats who want to make it impossible for people to spend their own money at fast food places have no problem letting food stamps be spent there. Sen. David Vitter is pushing this reform:

Sen. David Vitter, R-La., joined last week with three other conservative GOP senators to propose caps on means-tested federal social welfare programs. It would require that funding for food stamps and 76 other federal welfare programs be capped at pre-2007 levels by 2015 or when unemployment falls below 7.5 percent, whichever comes sooner.
It would require that food stamps be limited to essential foods such as milk and bread, as the senators said the program was originally envisioned, not, as it is in four states -- California, Florida, Arizona and Michigan -- for purchases at fast-food restaurants.
"One of the most significant substantive accomplishments coming out of the 1994 Republican takeover of Congress was welfare reform," Vitter said. "But as significant as this reform was, we are overdue to renew welfare reform efforts and make additional gains because the welfare state has grown enormously since then -- even factoring our recession." . . .