ringing in Outside Food and Drink
Disney used to have a policy "requesting" that guests did not bring outside food and drink into the theme parks, but this was completely unenforced. Now it has changed its policy, and guests are allowed to bring food items, such as snacks or foods that do not require heating, into any Walt Disney World theme park. It is also completely fine to bring in bottled water or soft drinks.
One note of caution: avoid bringing in anything highly perishable, such as cold cuts. It would be easy to end up with food poisoning!
Also, you absolutely will NOT be allowed to bring in the following: hard-sided coolers, large coolers, glass containers, or alcoholic beverages. Also, you cannot bring any type of straws (even the little ones attached to juice boxes) into Animal Kingdom.
I found this at:
MouseSavers.com - Disney World Meal, Snack & Drink Info - Discount Coupon for Orlando Restaurants