Mostly they are young girls on the brink of adolescence. They begin to diet and for a while are happy to be fashionably slim. But they don't stop there - they can't. They eat less and less until they are skinny, then emaciated, and ultimately skeletal. The girls who are not caught in time, in one of the strangest ironies of our affluent age, can die of starvation. What is this strange obsession that turns intelligent articulate girls into obsessive non-eaters? Doctors have a name for it-anorexia nervosa. But do they have a cure? Tonight's programme investigates and talks to some girls who are victims of this bizarre disorder.