Categorically not true.

No fast food on food stamps. No prepared food like the burrito at the corner gas station. No hot rotisserie chickens at Safeway or Kroger. You can't even get a hot dog at 7/11 however you can get a frozen pizza at 7/11 and cook it in their pizza oven which takes about 5 mins. You can also get Papa Murphy's take and bake pizza because it's not prepared.

Little known but you can buy vegetable seeds and even veggie starts on food stamps. It literally says what you can and can't get right on the USDA website.