Hi Sarah and welcome to the Disney Parks Moms Panel!
Food is permitted in the theme parks. You will need to watch your cooler size and keep in mind that glass containers are not permitted (with exception to baby food jars). According to
Park Rules, "suitcases, coolers or backpacks, with or without wheels, larger than 24" long x 15" wide x 18" high (61cm x 38cm x 46cm)," are not permitted.
We typically take a few snacks with us but we always enjoy the amazing food you will find throughout Walt Disney World Resort. The snacks and restaurants at Epcot have turned my kiddos into thriving foodies.
Les Halles Boulangerie-Patisserie is just one of many amazing Quick Service locations where you can pop in and enjoy a delectable snack! (I love the chocolate croissant!)
Thank you so much for sharing your question with the Disney Parks Moms Panel. Please let me know if you have any other questions as you plan your magical Walt Disney World Resort vacation.