I'm sorry to post so late to you, but I've been "out" for awhile.
I work 7P to 7A 4 days (er, nights) a week, and often convert to a day person on my 2 days off (after a day of total uselessness 1st day off) and not counting the 2 nights I go to school (falling on useless day and a day person day if I convert to day person). I can tell you what I do. I keep a running food diary and every midnight I add 30 more carbs to it. I usually keep it for a week marking the midnights with a * so I can see the days on it. I just keep it in the note space of my planner. Some days I have to cut back to keep in my limits, other days I can afford more or a treat if I've slept away my time or if I just didn't eat much (I work as a nurse - sometimes food is a fantasy).
I always pack a variety of options in my lunchbox - varying carb counts and varying food types. Then whatever my mood or allowance I have SOMETHING I can have. I carry in a grocery bag of stuff. They snicker sometimes at my BIG lunchbox. MY GOD are you going to eat all that. Well, probably not. Then I watch them going to the snack machine all night munching up mini donuts, zingers, chips and candy bars. Not to mention the pizzas they order or the crap they haul in from the fast food joints somebody runs to get if we can get loose.
I load up a convenient (but overpriced) salad bowl I like to buy at walmart, summer sausage and cheeses cut up, string cheese, leftovers, chocolate pudding (sugar free), boiled or deviled eggs, sugar free chocolate, celery with peanut butter or cheese spread, south beach meal bars, ... Then I eat when hungry, usually every 2-4 hours. I don't have "meals." That's for regular people. I may be eating spicy chicken at 5 am or scrambled eggs at 9pm. I don't worry about being conventional with the choices. I just eat what I am in the mood for and try to stay under my 30 carbs until midnight rolls around again and I get 30 more.