That's OK Detectivepotato- like I said, I know people don't mean to offend. I got that at school too- along with 'stick legs' 'ironing board chest' etc etc. Can laugh about it now.
I think often, people feel they are entitled to make comments about you're appearance if you're skinny when I doubt they'd make the same comments to someone overweight. Then some women see it as a positive thing- my DH says she is too skinny, wouldn't fancy her etc etc, when really it's just not nice is it?
The women in my ex's family do this. They are all slightly overweight, but feel it's OK to comment on my sister's weight saying she is too thin etc. My sister is gorgeous- think they may be a little jealous.