I work rotating shifts 5a-5p then 5p-5a. On my night rotation I generally bring smaller snack items with me to nip any hunger at random times. The problem is your digestion is not as effective at night, so your body will naturally gain weight if you don't monitor your food intake closley.

When I first started on nights a year ago, I was trying to eat a Smoothi 5 hours into the shift, then I would have a bowl of cereal or pop-tarts (not that healthy) around 3AM, 2 hours before my shift was up. Before I'd leave for work I'd eat a normal meal around 4 PM that consists of your typical Dinner (supper). Some people I work with fully rotate themselves and eat breakfast when they get in at 5P, and then have a large meal around 11P, followed by small snacks of donuts or honey buns around 8 and 3.

As of recently, I've changed my diet to consist of a Large Tortillia with half a can of veggetarian beans (no lard, fat free), 2% Cheese, some hot sauce, and if I need the extra boost some kind of meat. I eat this around 1030p and drink coffee hard throughout the night (no more than 1 pot over the course of the night). The coffee kills any extra hunger fits and gives me energy to stay alert during the work load. The burrito will pad your stomach and allow you to sustain that "full" feeling for longer without the need to keep snacking.

Stay active when you're off. Don't just sit around at home. The problem as mentioned with shift work or graveyard shifts, is your body will literally expand from your diet habits at night (someone once said its never a good idea to eat anything after the sun goes down). Stay active and mantain some kind of exercise routine between working days. Heck, wake up early enough to get some excercise in before work. I was paddling a kayak once a week for upperbody, and I peddle every other day for 6 miles around town just to get that little bit of extra exercise done. Some days it's hours hiking, some weeks it's too much over time to get any of it in.

None the less, monitor your in take and watch your weight. If you notice yourself rapidly gaining weight evaluate your meals again and reduce, space out, and add more sustainable products to your nightly meal plan.