A few things we have learned over the year traveling with our kids ages 4 and 6 now:
1. Pack a variety pack of your kids' favorite cereals (the little individual boxes). My kids LOVE this for breakfast b/c they think it's a special treat b/c they get a new cereal everyday. You can pick up milk at the food court every evening. If you don't have a firdge, just keep it on ice. Or, buy the milk in "juice boxes" that does not have be refrigerated. OR eat a big breakfast at the foodcourt (my kids like scrambled eggs and toast and it really held them over. Then see #3)
2. Also pack Juice Boxes if your kids are into them. It's worth the $10 a day for the fridge if they offer it in AS. Definitely buy water ahead of time if you can!
3. I learned that three meals a day was just too much for my kids. They were very happy to have "snack lunches". Pretzels and PB, etc. at the pool or before rest time.
4. The food courts are good. They also have an area where you can get a fresh fruit (banana, apple, etc.) and they have the little packs of PB, etc. The also have bread to toast, etc. Also, cold sandwiches, fruit and cheese, etc.
5. If you can do one character meal, do Chef Mickeys in the Contemporary. All of the characters are there and it is a blast! Dinner has a great desert bar with ice cream and different candies plus all kinds of deserts! They always have a kids buffet today which the kids love!
Good luck!