We generally eat pretty healthy here (well, I'm better with the kids than with myself and my coca-cola addiction), but yeah there's nothing "wrong" with giving them fish sticks here and there. When I've had to leave for a couple days to tend to my sick grandpa or whatever, I stock the kitchen with easy "man food" and let them do what they need to do. My husband knows my rule is that they can have milk at this time, juice at that time, and WATER is what we have in between. Other than that, I don't really care. Make sure they've got some cereal and fruit or oatmeal (super easy but healthy), lunch can be anything from a wide variety of sandwiches and fruit to macaroni and cheese or even a hot dog, snacks of fruit, veggie sticks, cheese sticks, and then dinner can be whatever they think is right. Dad may cook but just in case, I always provide him with a frozen lasagna and bag of salad, some PF Chang orange chicken for him and pot pies for the kids, a frozen pizza, or yeah fish. I prefer to give them the frozen fish fillets instead of the sticks (I guess I'm thinking it's a little more fish to batter ratio? lol!). That's also something I left for the babysitter sometimes. Make a thing of macaroni & cheese, the microwave mixed vegetable steamers, and some fish, then leave the sitter to feed it to them. I think if you do good most of the time, a few meals of "whatever" are not going to hurt them. It's more about a habit than legalism. :) Besides, it'll be good for dad and kids to have some time where he gets to parent and make his own impression with them; or maybe they'll go out to eat or to McDonalds to play in the playland. Thinking about Bill Cosby giving his kids chocolate cake for breakfast one day....they were fine, they were happy, there was no lasting effects of "childhood obesity" and diabetes. Just have stuff there in case they eat home, and leave it to him. Have fun on your trip!