When I'm working a normal job, or just looking for work, I have time to exersize and I snack a lot and have small meals, but when I'm working on an independent shoot (my own or someone else's) I don't have time or I'm too tired to workout and I can't always eat a little when ever I'm hungry and then I end up eating too much at meal times, which usually consists of bagels or pizza.
It's very different on a professional shoot. I still enjoy doing both.