This really only goes for if the person is older, but I find mostly the people who shamelessly ask this question are of the "greatest generation"...
Anyway an old lady at my gym today saw me getting out of the pool, and after making baby-related small talk said "oh you've gained a lot of weight" and then asked exactly how much weight I'd gained. For some reason, I just gave her the honest answer, which caused her to wag her finger in my face, tell me not to gain any more, and proudly announce to anyone within earshot that she only gained 20 pounds when she was pregnant.
Here's how I wish the conversation had gone:
"So, how much do you weigh?"
"Why don't you guess? And then I'll guess how many decades older you are than me!"
Re: An answer for when someone asks how much you weigh
I didn't know people this stupid actually existed.
Little old ladies though...like you said, different generation - I'd probably just say that my doctor was satisfied with my weight and leave it at that.
Anyways, I always tell her something like, I am right on track and the baby is growing so well.
I alway like it when men or women who are clearly bigger than I, make those comments! Ridiculous!!
This time she hasn't asked once.