KEY POINTS:
A click of the mouse grants you access to the deadly domain of the women who are literally starving to be thin. Welcome to the world of "pro-ana", an online community dedicated not to offering support and advice for anyone battling life-threatening eating disorders such as anorexia - but to preventing their recovery.
These 1000 or so sites feature "thin-spiration galleries" - picture after picture of skinny celebrities such as Victoria Beckham and images of emaciated women with their ribs on show and close to death.
These cyber-galleries and chatrooms, which claim that "being thin is more important than being healthy", have been condemned by experts who say they encourage users to compete against each other to lose weight. Clinicians say young women are turning to these websites because of a lack of proper support elsewhere and a lottery in treatment for eating disorders.
They blame the fact that adolescents and children are being fed conflicting messages about diet and health. On the one hand, they are the focus of anti-obesity campaigns, but then only have to switch on the TV to be bombarded with images of junk food or read magazines featuring images of impossibly thin women.
The fashion industry has also been singled out for criticism. A rising young model from Brazil died earlier this week from complications from anorexia. The collapse on Tuesday of 21-year-old Ana Carolina Reston, who had modelled in Japan and for Giorgio Armani, has already caused a storm of public hand-wringing in her home country and is likely to provoke fresh soul-searching in all the main fashion centres.
Psychiatrists say that while the use by designers of size 0 models on the catwalk - such as Lily Cole and Erin O'Connor - does not trigger eating disorders in an impressionable teenager, they can prolong the time it takes for them to recover. This is backed up by new findings published last week.
The first major study into female attitudes to thin fashion models has found that the models' images can lower levels of self-esteem and lead to higher levels of depression.
Published in the journal The Psychology of Women Quarterly, the research found that exposure to "thin-ideal" advertisements increased body dissatisfaction.
Eating disorders now affect more than one girl in every 100. Although 90 per cent of cases are female, boys are not immune. And while once anorexia and bulimia afflicted only well-educated and white middle-class women, now Asian and black people are seeking help, as well as those from working-class backgrounds.
Anorexia nervosa, in which sufferers restrict their food intake or starve themselves, is the third most common chronic illness of adolescence. Bulimia nervosa is even more common, but the secretive nature of the disorder means that it can go undetected.
Experts have identified a new type of bulimia. A third of patients seen by psychiatrists in eating-disorder clinics are "multi-impulsive", which means they binge on food then purge themselves, and also cut themselves, and abuse drugs and alcohol. Sane, a mental health charity, reports a rise in callers with eating disorders who are also self-harming.
The effects of eating disorders are damaging. Acid brought up from the stomach damages the oesophagus and erodes tooth enamel. In chronic cases it can cause kidney failure.
Hubert Lacey, an expert on eating disorders, said society's "preoccupation" with body size has contributed to the increase in severity of eating disorders.
"The preoccupation with weight and shape is ubiquitous because of the judgment on women," said Lacey, a professor of psychiatry at St George's Hospital, London. "One of the increasing problems women face is that desired body shapes change according to a woman's role, but the fact is they cannot change their bodies."
Increasing numbers of young people are turning to websites for support, but a University of Manchester report on pro-anorexia websites says these sites are regarded by sufferers as a form of "self-management".
Some evidence suggests more people are searching the internet for pro-anorexia websites. Research carried out by Hitwise UK, which analyses internet traffic, has found one pro-ana site has gone up in popularity ranking from the 350,000th most-visited site a year ago to the current frequency of 40,000th.
Ulrike Schmidt, an expert on eating disorders, says patients who look at "pro-ana porn" are delaying their recovery. "People with anorexia see it as virtuous and a good thing, and that it has a meaning," said the professor of eating disorders at Kings College, London. "But if you surround yourself with this pro-ana porn it could keep you ill."
- INDEPENDENT