I think that being blunt can be beneficial for people. First, they will learn how to cope when faced with truth and secondly, words are meant to help them lose weight and get their health better. I have a fat friend and I do call him fat and he laughs and make jokes as well. I see no problem with it. It is in our nature to see things and make a judgement on things. Whatever we see, we do have an opinion and that's very good. Why being fake and say what people want to hear?