Replies to 'Breaking Unhealthy Habits'

 I know the trap of "just one won't hurt" and "oh try it" and "come on, I made it just for you!"
I once had to say in public that yes, this once WILL hurt me, and that they must have had somebody else in mind when they made it because I've told everybody that I'm on a diet and "that's not on my menu."
I was afraid the other person would take serious offense, but I did it anyway because not to would have been caving in yet again. (This person was notorious for noticing EVERY pound that I gained and commenting on it, but turning around and pushing sweets etc.)
As it turns out, this person dropped the matter and never pushed food again.
What you fear as a reaction from others to your stand usually never happens. And if it did, if this person had got mad, so what?  My health, self confidence, and self image are far more important than someone else's inaccurate perceptions. That's their problem to overcome, not mine.
Oh, and the old "diet at home" thing, tell them if you were home right now you'd not only be avoiding food but working out! So thanks for the break!