For breakfast, we usually get cereal and bananas (milk in the fridge in the room). Pretty easy for a quick breakfast. [I also highly recommend getting some chocolate chip muffins from Epcot at Sunshine Seasons - they're fabulous! (When we went to Epcot, I would always buy one for breakfast the next day.) Not especially nutritious, but they're really good!]
For snacks in the room/at the pool, we got cheese and crackers, peanut butter crackers, salsa and tortilla chips, cookies and fruit. We do most of our eating at the parks, including snacks, but it was very handy to have some more substantial snacks when we went on our last trip - we got stuck in the room for the better part of a day during Hurricane Wilma! They asked us not to leave our rooms, so it was great to have some things to snack on. I'm sure the restaurants at our hotel were packed, since everyone was confined to the resort until the "all clear" was given, so we were so happy to have some stuff to eat.