Vulnerable young people are being lured into starving themselves, or binge eating and throwing up their food, by websites that glorify "pro-ana" lifestyles, say health campaigners

The comments come after The Independent on Sunday highlighted concerns last October about the images and advice on such websites.

Pro-ana sites, which frequently present themselves as support networks, have come under fire for discouraging people from seeking the real medical treatment they need. Steve Bloomfield, from the Eating Disorders Association, claimed that the websites are "literally killing people".

"The danger of these sites is that often young people with an eating disorder don't understand what is happening to them," said Mr Bloomfield. "They are very scared of talking to their parents or teachers or doctors, so they turn to the internet for information."

Some of the sites offer tips on weight loss alongside images of slim celebrities and models.

Amanda Hills, a psychologist and counsellor from the National Centre for Eating Disorders, said the sites "keep people in their illness" instead of directing them towards medical help.

Those who resist treatment are also at risk of infertility and osteoporosis.

Mr Bloomfield added: "About one in five people who don't get appropriate treatment die prematurely, so [these websites] are literally killing people."