In our modern society, the cult of celebrity and the ubiquitous display of perfect airbrushed faces and bodies on advertising pages and hoardings mean that children are more body conscious than ever before, with children as young as eight feeling the need to diet.

They aspire to be thin and beautiful like the film stars and models that they see in magazines, and they believe that they will be happier and more popular if they conform to the right image.

Sadly for these young girls, and increasingly young boys, research shows that those who start dieting before the age of 14 are far more likely to be constantly on diets and to find it hard to maintain a permanent weight. It is believed that early dieting may disrupt the metabolism of teenagers, and the research also shows that, perversely, adolescents who diet are most likely to become obese adults. This pressure to conform to an artificially thin body image coinciding with new and erratic eating patterns of adolescent and teen years, with the added complication for girls of the onset of puberty (which can mean a change in body shape), may contribute to girls and some boys developing eating disorders in their early teens.

Going to extremes

Between 5 and 10 per cent of adolescent girls show some signs of eating disorders such as anorexia nervosa (severe dieting and weight loss) or bulimia nervosa (bingeing and purging). The incidence of these disorders among boys is negligible.

It is at the stage of puberty when girls are becoming more curvaceous – which many struggle to accept – that these disorders can begin. Young sportswomen who have to be thin for their sport, such as gymnasts and longdistance runners in particular, may dislike the changes to their body shape.

However, severe dieting during puberty can affect growth and delay the onset of menstruation. For those who have already started their periods, these can become erratic or disappear altogether. Both anorexia and bulimia can have serious effects on the long-term health of your child and, in some cases, be life-threatening. At the first signs of either of these disorders you should seek professional help and advice. Signs of anorexia nervosa include:

- She expresses dislike of her body image.

- She toys with her food, cuts it into very small pieces and eats very slowly and very little.

- She avoids eating with the family.

- She loses significant weight over a short period of time.

- She wears baggy clothes to cover up and hide her thinness.

- She exercises excessively.

- She is obsessive about calories.

- She weighs herself compulsively – perhaps several times a day – and is distressed by any fluctuation.

- She stops having menstrual periods.

Although much more widespread, bulimia can be harder to spot because there is no drastic weight loss. However, other signs to watch for include:

- Her weight swings up and down by as much as 4.5 kg.

- She spends a lot of time in the bathroom, especially after meals.

- She binge eats without appearing to gain extra weight.

- She complains of sore throats and difficulty swallowing, induced by constant vomiting (tooth enamel can also be damaged).

- She excessively exercises to compensate for overeating.

- She has irregular or absent periods.