What an insensitive thing to say. Why can't people be a bit more subtle?? One time, my ex indicated that I had put on a bit of weight by putting his hands on my belly and WOBBLING it. In the middle of a pub. I nearly smacked him. I was more offended because we had discussed it before, with me saying that sometimes his actions are a bit insensitive, so he got all offended and was like what's your problem, stating that that is how he would prefer me to tell him that he was putting weight on. I would have preferred if he'd said 'maybe you should go to the gym a bit more' or something like that, rather than making such an obvious, public display of it.
Another time, I went to meet my friends and one of them (male) greeted my with 'hello fatty'. I gave him such a glare, and he couldn't see what my problem was. I know he was joking but there must have been an element of truth for him to say it in the first place, and at that point I was very sensitive about my weight.
Most men just don't understand.