[CN: weight and body size discussion]
So, I was just outside walking the dog and our friendly mail carrier drove up to deliver the mail. Intending a compliment, I'm sure, he said, "You look--even skinnier, or something." I must have looked a bit stricken as I started mentally checking any signs that I could have lost weight in the last couple months (one of the first questions on my paperwork every time I go to the rheumatologist). He saw me freeze and said, "I though maybe you've been on a diet or something". Such "Have you lost weight?"-type "compliments" are likely reflexive, especially during the holidays perhaps.
I had the urge to drop it, but I told him that I got a funny look on my face because I have a chronic autoimmune illness that causes intermittent rapid weight loss, and I was already chronically underweight, so my doctors follow my weight to make sure it's stable. He seemed receptive and wide-eyed: "Oh, really!?", like he had no idea one could actually be too thin, or that thinness is not necessarily a sign of health. Maybe it was over-sharing, but I want him to think twice before commenting on someone's size and/or weight and/or dietary habits the next time. Or maybe he'll just think I'm a weirdo--fine.
If he wants to hand out compliments with the mail, he should probably stick to stuff like, "Hey--cool boots!" I had some seriously cool boots on and everything.