New guidelines aimed at improving the care of people with eating disorders have been issued by an NHS watchdog.
Half of all people with anorexia are teenage girls
The National Institute for Clinical Excellence, (NICE), set out treatment plans for patients with anorexia, bulimia and binge eating disorders.
It made specific recommendations for the care of teenagers, because of the rising numbers hit by the disease.
NICE also stressed the importance of psychological treatments and called for increased awareness among GPs.
Experts said the guidance raised awareness of eating disorders, but did not come with any extra resources.
In the UK, around 1.1 million people - including children as young as eight and some over 65s - are estimated to have an eating disorder.
However 50% of people with anorexia nervosa are teenage girls aged between 13 and 19.
And the average age for developing bulimia nervosa is between 17 and 21.
The NICE guidelines set out specific treatment plans for each eating disorder.
And they say that, where the patient is a child or adolescent, treatment should be tailored to their age and should involve carers and family members.
The guidelines will be sent out to GPs and mental health specialists, and an information booklet will also be produced for patients and families.
Andrea Sutcliffe, who led the development of the guidance for NICE, said: "The availability of NHS services for people with eating disorders varies across England and Wales.
"With about one in 250 females and one in 2,000 males experiencing anorexia in adolescence or young adulthood and about five times that number suffering from bulimia, this guideline is an important step in standardising the care available to people with eating disorders.
A spokesman for the Eating Disorders Association told BBC News Online: "These guidelines are very good, but we are concerned that the NHS doesn't have the infrastructure to deliver them.
"Two years ago, the Royal College of Psychiatrists reviewed eating disorder services and found there were 25 specialist services, which represented around 50% of what there should have been."
He added eating disorders could have a particularly devastating impact on teenagers.
"It's very difficult for them to develop to their full potential. Their education can be disrupted, so for example, they might not go on to get their university place they are could easily have gained."
Jane Nodder, patient representative on the eating disorders guideline development group, said: "I welcome this guideline as a way of introducing a benchmark for the management and treatment of people with eating disorders.
"I am particularly pleased to see that it highlights the importance of patients, carers and health professionals working together to make treatment decisions and to provide good quality information to patients and their families."