Anxious mothers often watch teenage daughters like hawks, convinced that the slightest sign of disinterest in food means the start of anorexia nervosa. But the illness is relatively rare - only three out of every hundred adolescent girls are affected. The usual age of onset is 14 or 15 years, though it can exist in children as young as eight. Only 10 per cent of sufferers are boys.
Anorexics develop a phobia of being a normal body weight and have an obsession with avoiding food. They starve to an often dangerously low weight. The word anorexia, meaning loss of appetite, is misleading, since anorexics are ravenously hungry and think about food at all times. One aspect of the illness is an obsession with preparing food for other people.
They are so petrified of gaining weight they will avoid food at all costs to stay thin. Anorexia is about control and often starts with a diet triggered by feelings of inadequacy or being overweight, often following thoughtless comments by others about body size. A sufferer enjoys the compliments prompted by weight loss but then can't stop dieting once the goal weight has been reached.
About half of anorexics binge and purge but this should not be confused with another eating disorder, bulimia nervosa, where there is no phobia of normal body weight.
Anorexia is dangerous and 10 per cent of long-term sufferers die. A fifth recover, two-fifths develop bulimia or compulsive eating, while a third remain anorexic.
More common is the eating disorder bulimia nervosa, which usually affects older teenagers and young women. Reported cases show 10 per cent of female college students are affected but the real figure is thought to be much higher.
