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but then again, I wish people wouldn't comment when you put weight on, because they must know it's offensive.
I suppose it depends on what the individual who is doing the name-calling has been through themselves. We all have something we don't like about ourselves, and/ or a situation we've been through that is sensitive. Every one of us has something that will push that button. And quite often, what we hate about ourselves is what some others desire to have. Like the thing about my lils (sorry 
it's the best example I can think of) I was talking to my very tall, very pretty, very slim friend about it and she's telling me to stop moaning cos she would love not to look like an ironing board and wishes her feet weren't like paddles! I then went on to remind her she's got legs like a giraffe but she doesn't see what I and others see. Sure, she knows how to 'sell' her good points, but her brain emphasies on the negatives she feels about herself. And she also finds it difficult to gain weight and hates it, whereas if she loses more than 7lbs she feels she starts to look anorexic and gaunt, so it can be very much a 2 way street.