Anorexia affects mostly girls though there has been a rise in the number of boys who are reported as anorexic.

It generally begins in mid teens though children as young as nine are reported to be dieting and may be putting themselves at risk. A third of anorexics were overweight as children.

What is anorexia?
Anorexia is an eating disorder characterised by an obsessive desire to lose weight and a distorted body image. Though sufferers are painfully thin, they see themselves as fat and starve themselves to prevent weight gain.

They may also use other methods to lose weight, like making themselves sick after eating, dosing themselves with laxatives or excessive exercise.

The list of common symptoms below are a useful guide. But, as with any other serious health issue, always seek professional advice at the first opportunity.

Physical changes
Anorexics appear painfully thin. Girls will often wear loose-fitting and layered clothes to hide their thinness. Layers of woolly clothing may also help to keep them warm as the drastic change in weight often causes a drop in body temperature.

As their stomach contracts due to the low food intake, sufferers complain of abdominal pains after eating. Lack of food can cause bouts of constipation and large quantities of laxatives may be taken, partly for constipation and (more likely) to get rid of any food they have eaten.

When body weight falls below a certain level, anorexics find that their periods have stopped. If anorexia occurs before puberty, it will stop its onset. Skin becomes dry, nails become brittle and a growth of downy hair may appear on the face.

Changes in eating habits
A teenager suffering from anorexia may skip family meals, claiming that she has already eaten. She avoids eating with others and snatches 'meals' at odd moments of the day. Food may be cut up into small portions and pushed around the plate. Bulky but low-calorie food, such as celery or lettuce, is piled high and substituted for more substantial food.

Changes in behaviour
Anorexics may exercise excessively, though their weight loss makes them weak and easily tired. They may count calories obsessively, read slimming magazines avidly and weigh themselves several times a day. Surprisingly, though they eat very little, anorexics are preoccupied with food and often love to cook for other people.

Seek professional help as soon as you can
Anorexia is a serious illness and, in a small percentage of cases, fatal. Argument and persuasion from family members will not help. The underlying condition is a form of mental illness and the sufferer needs professional help - the earlier, the better. Ask your GP to recommend a specialist clinic.

Provide support and encouragement without intruding. For many anorexics, it appears that their weight is the only area of their life in which they have control. They may therefore be very resistant to getting treatment which they feel will take away their control. It is vital to approach the matter delicately.