A few years ago, Florida's theme parks were very strict about bringing any food or drinks into the parks.
In recent times, these rules have been relaxed a bit and most parks including Walt Disney World, Universal Studios and SeaWorld will now allow you to bring a reasonable amount of food and drink into the park with you.
If you turn up with a full blown picnic basket don't be surprised if you are stopped
Remember that in today's heightened security world, all bags and containers will be inspected at the gate. I've seen people have cans of soda "confiscated" at the security checkpoints before now so they do enforce their policies.
Generally, most parks will allow you to bring in the following items:
- a small soft-sided cooler, typically no larger than 8.5" wide x 6" high x 6" deep (big enough for a drink six-pack)
- bottled drinking water
- juice boxes (without straws)
- single servings of snacks that do not require heating
- baby food, formula, bottles, jars and other baby related items
- special dietary food including health, nutrition and medical related food stuffs
- opened single serving soda drinks
Most parks still ban the following items:
- alcoholic beverages
- glass containers (except baby food jars)
- straws and other plastic items like lids that could endanger animals
- hard-sided ice chests or large coolers, bags on wheels, suitcases
- unopened soda, sports and energy drinks
- picnic baskets, sandwiches, loaves of bread and meals
- large servings of snacks
If you do bring in your own drinks or snacks then you are not expected to consume them in any of the park's own restaurants. You will have to find other seating areas to eat your snacks but that is usually not a problem.
Also, bear in mind the day time temperatures so make sure any food you bring with you is adequately cooled. The last thing you need is food poisoning !!