This is another challenge. How to "not upset the host" :-) and also have a nice time at the party or at a restaurant or in someone's home ? The best strategy is to eat at home before you step out. Nothing beats this. However here are a few ways to have fun from starters to dessert.
Also keep a box of Splenda minis dissolvable tablets in your car. In case the place you are going to does not have it.
Request for a cold club soda and squeeze a lemon into it and add Splenda. Munch on carrots, tomatoes, salad and celery along with your drink. Go easy on the dip.Its likely that it is not fat free.
Focus on lentils, soups, beans, veggies, yoghurt. Greens and beans are better than potatoes.
Fresh fruits like oranges, strawberries (with some fat free cream if possible). If yoghurt is available then add Splenda to it and have it as a dip for your fresh fruits