1) Eat a small, healthy meal before you go, so you won't be extremely hungry and loose your focus.
2) Bring some of your own, healthy, properly proportioned items. (Ex: bring your own pretzels, so you don't eat their chips)
3) Eliminate one of the items all together. Ex: You can have a hotdog, but no potato salad.
4) Don't eat the buns on the hot dog or hamburger -- that alone will save you close to 300 calories.
5) Choose to eat what you like, but limit your portions. Example: Split a burger with a spouse/friend, only put 1/4 cup serving sizes of the beans, potato salad, etc. on your plate. Enjoy the desserts, but only put 1/2 the amount on your plate (1/2 cookie, small brownie, etc.) This way you can have more, with less!
6) Stick to water only.
7) If you don't feel you can make good choices, don't go. This is extreme, but think of it in terms of an A.A. member going to a bar--it just doesn't work!
8) Once you do eat, don't let yourself immediately get up and get more food. Tell yourself that you have to wait a minimum of 15 minutes first. At that time, if you are consciously still hungry, you can get more (within reason). This technique works well. It allows our mind the time it needs to make the connection with the stomach.
9) Move. Play. Walk. Hop. Skip. Jump. Run. Move, because you CAN!