Anything with protein and complex carbs. How about a turkey sandwich with whole wheat bread, lettuce, tomato and some yogurt. Or a proper meal such as rice,beans and chicken (depending on what time of the day it is). For a snack apples plus a little peanut butter to dip in is excellent..or cheese sticks and whole wheat crackers.

I would stay away from junk food such as chips or sugar filled candy bars/granola bars or even juice which is pure sugar and move towards complex carbs + protein.