You don't know what junk food is? No chips, no snack cakes, no soda.
You can spend all day asking about each individual food item, or we could not pretend we're 6 years old and just have foods it does apply to, like meat and produce, frozen food section that isn't ice cream, and probably dressing/condiments. It's not 100% of their food budget, so if they want chips, fudge rounds and sodas, they can buy it with their own money. If they're spending 15% of their benefits on sodas, we can either limit what foods it applies to, or cut their benefits by that amount, because there is 0 nutritional value added with that money,