I worked nights for a while and really could not adjust well to the sleep deprivation. I read in "Fight-Fat After-Forty" that eating later at night makes some people gain more weight.
The mantra was "After 8(PM) gain Weight", this was true in my case. I started eating before my shift and not during it. I also realized that I was not getting enough sleep and eatting more for energy.
Just some things to consider.