My number one rule is, when travelling, none of the following rules apply; my number two rule is don’t be an assbite about it, and at parties/dinners, or whatever, eat what is served:

No caffeine, only crappy decaffeinated coffee;
No soft drinks;
No milk products, yogurt and goat cheese excepted;
No wheat, as far as humanly possible;
No potatoes.

When I stick to this I feel better, when I fall off I feel worse.