Gas station food should be quick grab snacks and not fully fill you up like a restaurant meal. What if sport lunches / water only filled you up to a maximum of 30-40%. Would always be available to get if you ever really needed it, but then would force customers for businesses to fully satisfy their hunger. Restaurant food/drinks could then fill up to 100%. No one will want to carry 12 sportlunches so going to convenient stores for food would become less prominent since that would be an emergency or last resort for if you ran out of other food and just needed a snack to keep you going.
There are multiple changes coming for this.
Food and water diminishing slower
Food from restraunts will be the standard way of getting food moving forward.
Vending machine food and water will be very little, almost as if its an emergency method of getting food.