Yes, it would be great if you could do with a 4-5 hours shooting, but usually our experience is 8-12 hours ones, so we needed to offer three meals (breakfast, lunch and tea).
We have prepared food ourselves for some shootings too. Catering or hand-made, that's up to you, but you always need to have water (loads), juices or soft drinks, coffe & tea and snacks (sweet and salty) at all times. Also for the food, be prepared to have some variety in case some members have special needs (no sugar, etc)
Hope it helps!