I really wouldn't want to get into such detail every time I declined a piece of cake. About diabetes and how sugar affects me and all. That can get quite tiresome and be a real downer at a party.
I still think a simple "Looks great, I'll pass for now though", is more then sufficient. If someone would press me, then maybe, just maybe I'd mention that it just doesn't agree with me.
As far as taking a piece and then having a bite or 2, well for ME, that just wouldn't work. 1 or 2 bites can easily turn into the whole piece, and then some ice cream and then some who knows what. I do best with definite "no's".



Me too! One of my rules is that if it's someone's birthday, I get to have a piece of birthday cake. I don't care who's birthday it is. If I'm in a group of people and birthday cake is served, I'm eating a piece of it. The whole piece and the icing, not just one or two bites and then throwing it out. I'm not going to gain all 35 lbs back with one piece of birthday cake. I'll frequently allow myself dessert in other situations as well. I want to be thin, but not at the expense of eating birthday cake.
Luckily, in most of the groups I'm in, it's not really socially acceptable to have two pieces of cake, so having a second piece isn't a problem.