LiannaKole & chubbySister One thing that's helped me avoid unnecessary foods is to realize that in 10 minutes, it really doesn't matter if you ate the cake or bacon or whatever. I have dietary restrictions, and one Thanksgiving there weren't any desserts I could eat, so I sat awkwardly while everyone else had pumpkin pie and cookies, feeling pretty down that I couldn't have any. Fifteen minutes later everyone was done and we were chatting and playing games, and for some reason it really hit me how fleeting my sadness had been. Even though it felt so important in the moment, I'd forgotten it so soon. Ever since then it doesn't affect me when I can't eat something that other people can.
Good luck with your parties - you can do it!