As the start of London Fashion Week reignites the debate over ultra-thin models, psychiatrists have called on the British government to act over the soaring numbers of pro-anorexia websites.

Encouraged by social networking sites like Facebook and thinspiration websites, growing numbers of Britons are looking online to get tips on how to starve themselves or hide extreme weight loss, says the Royal College of Psychiatrists.

(These) websites normalize illness, said Professor Ulrike Schmidt, chair of the college's eating disorders section.

In much the same way, the catwalks of international fashion events such as London Fashion Week can act as a showcase for underweight women.

Fashion Week organizers have refused to rule out using waif-like models on the catwalk.

More than 1.6 million people in Britain suffer from eating disorders, nearly 90 percent of them teenage girls.

The report calls on the government to tackle the proliferation of pro-eating disorder sites as part of its wider efforts to safeguard children on the internet through the UK Council for Child Internet Safety (UKCCIS)

Psychiatrists say 1 in 10 girls look at pro-eating disorder websites repeatedly, taking inspiration from celebrities like Lindsay Lohan and Paris Hilton. Some websites use photographs of excessively thin models and messaging forums to encourage severe weight loss.

Beat, a charity for people with eating disorders, said steps to make the sites illegal would not solve the root problem.

Directing people away from these sites, toward pro recovery sites is what we would wish to see, said its spokeswoman Mary George.

Beat said it is already working with the AOL internet service provider to filter searches.

If somebody puts in a search for pro anorexia websites, our website comes up first, said George.

The UKCCIS said it was working hard to ensure that vulnerable young people are signposted toward places where they can get help when accessing such sites.

(Editing by Steve Addison)