I've worked shifts for many years now, earlies, lates and nights. I'm lucky in that I have access to a kitchen so can take easy food to work. Also unfortunately I can eat all night without any problem.
I suppose I just eat normal easy foods, beans on toast/jacket. sardines on toast, various salads, sometimes packet pasta and sauce. If i've cooked at home will take in leftovers (if I ever leave any!)
I do make sure I take plenty of food on a night shift so I wont be tempted by the biscuits already in the cupboard, so plenty of fruit, yogurt, sugar free jelly, anything to keep me munching into the wee hours and to stop me from falling asleep. Carrot sticks and dips are another good one.
Good luck.
Vanda