From their website:
Acceptable items:
Bottled water
Small snacks that do not require heating
Any food required for medical purposes and medicallyindicated nutritional supplements
Any food required for special dietary needs
Baby food/baby formula
Soft-sided insulated bags no larger than 8.5" wide x 6" high x 6" deep
Prohibited items:
Picnic lunches
Food that requires heating or refrigeration
Alcohol and glass containers
Hard-sided coolers
Soft-sided coolers larger than 8.5" wide x 6" high x 6" deep
Coolers, suitcases, and bags with wheels
Please be advised that all bags and personal items are subject to inspection.