When it comes to people loving their bodies, *cough* not masturbation *cough*, if they're not comftorable with the way they look, it's because not enough people are telling them how good they look.
Most women are insecure because not enough guys tell them they're beautiful *looks at the dads* go on, start telling your daughter she's a beautiful princess, just don't say she can't do anything wrong....
And guys? Well, well don't tend to care as much about our appearences.