The Agriculture Department announced Tuesday that it proposed new rules that would require retailers to stock a much wider variety of fresh, healthy food in order to continue accepting food stamps.

Under the proposed rules, retailers would have to stock seven varieties of each of four food groups—fruits and vegetables, breads and cereals, dairy, and meats/poultry/fish—and include fresh options for at least three of those categories. The rules would update current requirements that retailers stock three varieties of each food group.

“USDA is committed to expanding access for SNAP participants to the types of foods that are important to a healthy diet,” Kevin Concannon, the USDA’s Under Secretary for Food, Nutrition and Consumer Services, said in a statement. “This proposed rule ensures that retailers who accept SNAP benefits offer a variety of products to support healthy choices for those participating in the program.”

The proposed rules are designed to give low-income families more access to healthy foods, but they also might force many convenience stores to stop accepting food stamps. Convenience and dollar stores are often the only source of local food in food deserts.

About 45 million Americans use food stamps to subsidize their food expenses, and more than a quarter of a million retailers are authorized to accept food stamps.