I don't tell anyone that I'm "primal" or "paleo", mostly because the majority of people wouldn't know what the heck it was . If I tell people I don't eat grains or sugars (which is pretty much how I sum it up) I do sometimes get the "but grains are healthy!" response.
My friend acted as if my new way of eating was a personal affront to her... cause, you know, she can't feed me crap anymore now. She also tells me that I'll look "skinny and ugly" when I get to my goal weight (which is a BMI of 20 so hardly skinny and scrawny...). When I tell her I used to be that weight and I wasn't skinny, she says "yes, but you're OLDER now" as if that has somehow magically changed my physiology so that what looked fine and not at all skinny when I was 20 will suddenly make me look gaunt now. (It kinda pisses me off... I try not to bring it up with her, but she made some stupid bet with me that I couldn't lose the weight, and stupidly enough I took her up on it because nothing pisses me off more than telling me I can't do something!!).
So yeah, most people wouldn't have a clue what I do nor not as far as eating goes, and I'm happy enough to keep it that way. When I have lost all the excess weight, if people ask what I did, I'll tell them... They'll either be receptive to it or not! (Most likely I'll get comments about being "too skinny" or something ridiculous which is what happened last time I lost weight... and no I wasn't skinny at all, I still had rolls of fat... it's just weight loss around these parts seems threatening to people in some way. It's okay to be naturally thin, but god help you if you've actually gone from overweight to slim!!).