Flo's Cafe is on Deck 11 between the kids/family pools and Cabanas (the buffet restaurant). They serve pizza, sandwiches, wraps, fresh fruit, burgers and chicken tenders and are open 11am-7pm.
http://disneycruise.disney.go.com/ships-activities/ships/fantasy/dining/flos-cafe/
Cabanas the buffet restaurant isn't open continuously but they do have long hours at breakfast and lunch. They close for about an hour between meals to clean and do the switch over for the next meal. For dinner they become a sit down restaurant. You can always grab something from Cabanas to keep in your stateroom too.
http://disneycruise.disney.go.com/ships-activities/ships/fantasy/dining/cabanas/
Room service is open 24 hours a day (except for the last night), but the quick service counters by the pool do close down occasionally. The hours are always posted in the Navigator.I've been researching Fantasy stuff for our upcoming trip & what I've read seems like the staff is very very accommodating if you just ask too
I know that was a typo, but it still made me laugh.Drink stations are always open as well. A quick soda fix may help. Our DD is a Type 1 diabetic so I can relate. We always keep snakes and glucose tabs handy at all times when traveling.
If you need to find out carb counts for any reason that is not so easy! I have even spoken with the Chefs on board about it. One thing Disney is not so great about. We have just adapted.
I believe the Cove Cafe has snacks available as well. The coffee costs extra, but not the food.
I know that was a typo, but it still made me laugh.