But why do so many people now have eating problems?

One reason appears to be poor self-esteem. Certainly many eating disorders begin when young people become convinced that if only their bodies were more perfect, they would feel better about themselves.

There are also issues of control. If young people are bullied, or even just living in bossy or super-achieving households, they can easily feel that everyone else controls them. To counter that, they seek out some way in which they can be certain of exerting some real control of their own. And many of them choose to have ultimate control of their own bodies by rigidly governing how much food they'll allow to pass their lips. The sense of power can be very elevating - at least initially - and having had this kind of excited 'fix', most young people are reluctant to relinquish it.

Another cause of eating disorders is undoubtedly media pressure at a time when a young person is feeling vulnerable and awkward. But there is some suggestion that a person's genetic make up may make them more prone to eating disorders than other folk are.

Unfortunately, some young people suffer traumatic events such as bereavement or sexual abuse in their early years and there is substantial evidence that such episodes can trigger problems with food.

Also, households where there are high academic expectations are well-known breeding grounds for eating disorders .

Finally, many young women between the ages of 15 and 25 develop an eating disorder when they are not only under stress at school or college but also uncertain of their sexual orientation or sexual attractiveness.