So I've seen quite a few posts on here discussing the matter of sharing, or not sharing, our weight loss efforts with colleagues or people we just happen to eat with (so they see we're not eating certain things, and comment on it).
As I've already mentioned somewhere on here, I'm not very open and easy going about my weight loss. That is, I share with close friends, but I don't see a reason to be a target of (uncalled for) advices, tips, questions and general chit-chating about how fat I am ("you don't look fat at all!")
Fortunatelly (haha!) I suffer of Crohn's disease, which is a digestive disroder. It also means I have to modify my diet to stay well. Having an uncurable condition has one major advantage: people don't question me twice if I refuse to eat something. I can't eat the fries, I can't have the cake, sorry, sorry. For health reasons. Period.
So my advice is, if you don't want to go into details about your diet, just make up a health condition that prevents you from eating junk. Stomach ulcer, irritable bowel syndrome, whatever works for you. It ought to be something everyone knows, or heard of, so they can imagine what you're talking about True enough, people might want to talk about your condition instead (give them all the juicy details I say!!!) but you're off the hook as far as diet is concerned. Even the most stupid and pushy people will back off once you explain them the frequency and consistency of diarrhoea this particular cherry pie would give you if you took a bite!