I've gained about 70 pounds before -- and I've lost 70 pounds. In my mind, I suppose I've walked in both shoes. Maybe subconsciously or something, I feel like I can call it out. Do I do it to strangers? Hell no.. Hardly anyone does that. And with friends, it's merely funny observations.. I might slap my friend in the gut and joke or something IF I see he's been packing on pounds. The last thing he or I are worried about is him crying over it. That's not the reality I or my friends live in, and I don't have to worry about that level of sensitivity. If someone's really obese though, I say nothing. It's obviously not the easiest thing to live with, and they know enough about themselves as it is.
If I sound defensive, I don't mean to be. Just kind of indirectly responding to all of this right and wrong talk. I'm not an asshole about people's weight, but I might poke a friend or two about it. And if someone LOST weight, I sure as hell don't refrain from pointing it out. I think it's great, and that they look great.. I don't get what the problem in telling someone that.