This is a hard one- I drink and don't eat because I know there are so many calories in the alcohol I drink!
Could you not clamp down a bit the previous day/s before you go out to drink?
Failing that, could try things like pitta filled with lean meat like chicken- eating something more filling could be a better option as your less likely to pick and keep on picking -which itself can lead to all sorts of trouble! Also if you have just one, largish thing your less likely to want dinner separatly to it.