I know what you mean. I tend to run on about 4 hours of sleep a night on week days, so I'm like that all the time, pretty much.
I find that it helps to get yourself as far away from food as possible so you don't do it unconciously, get yourself something to do (which you probably already have if you're up late), or, if it's not working, have some water. It usually works for me, especially if it's seltzer.
I also find that I feel really sick to my stomach if I don't sleep enough after a while. Maybe it balances out a bit.