Most restaurants are really cold, which always makes me want to order something hearty and comforting. If I get a hot water with lemon (hot tea would work, too) and warm up a little before I order my meal, I'm much more likely to order something that's actually good for me.
If you're drinking as much water as you should be, you're probably heading to the bathroom quite often. Before you allow yourself to sit back down in front of the TV/computer/whatever, do a quick little chore. Oh, and drink some more water. :-)