Whats wrong with it?

When some people lose weight and start to look good, the vanity that drove them to do it in the first place still remains and they need constant attention and compliments, thus changing the persons outlook on life, way of thinking, beliefs, ethics, values, morals, how they treat others, how they think others ought to treat them. Some turn into terribly vain people because they choose the WRONG reason to lose weight (in this example)