You should be on diet....

I agree. Not all women likes to hear this kind of comment. Might be this girl already accepts and enjoys herself being what she is. In that way, she is already contented with whatever she has. Being happy means being contented of whatever you have in your life. You to accept and love yourself. No matter how bad those comments that you would hear from other people, id doesn't matter. As long a you know it to yourself what matters most and priority in your life.

I think, that phrase is now so prevalent and becoming a joke. With the emergence of fast foods and its popularity with the people , you could already see a lot of obese persons if not chubby on the least. People with big bellies are now a plenty. Hence, this phrase is now a so common phrase, because they sometimes use it to tease somebody who eats voraciously, without heartily meaning that the person is so fat that you have to say "you should be on diet"!

i think this kind of expression has made itself a cliche that women could make a fun out of it. among friends, if this is said, it can appear like a joke. if the person saying it means the words s/he says, then the woman who receives it may take it as a friendly advice. besides, it is a usual remark for chubby girls. if it still hurts, then it must be true.