Order from Von's or Albertson's and arrange to have it delivered to your hotel room. There are many posts on here about how to do that, and how to waive the delivery fee.
Order a case of water and bring your own into the parks. Get crystal light or kool-aid single packs to put in your water bottles. Refill your empty bottles at the baby center in DL for free cold filtered water.
Bring in your own high protein snacks (jerky, frozen gogurt tubes, cheese sticks, trail mix, etc.). These kinds of snacks stick with you so you don't get hungry as often. We like to do peanut butter and honey rolled up in flour tortillas for an easy, portable snack.
Split meals in the parks. Adults can order kids meals at counter service restaurants.
Those are a few to get you started. . .