Members of families that receive benefits from the U.S. Supplemental Nutrition Assistance Program (formerly known as food stamps) are more likely to be overweight or obese than people in families that don't receive the federal food assistance, according to a UC Davis study cited by ABC News. However, the research doesn't say its the food assistance that is making them fat.

The argument that excluding "unhealthy" items - like candy, soda and chips - from the supplemental nutrition program would make participants healthier "is not a lay-down hand at all," said Julian Alston, professor in the Department of Agricultural and Resource Economics at UC Davis.

"You can restrict how people spend their stamps but not change their total consumption," he said. Also, manufacturers will tweak their products to try to get around the prohibition. "They will re-engineer the food," Alston said.