They glorify snapshots of women with their rib cages and spinal columns protruding.
They also give such tips as how to hide an eating disorder from friends and family. Or how to trick doctors into believing you're gaining weight by stuffing your pockets with weights.
Dozens of sites that promote anorexia -- and the related illness bulimia -- as a lifestyle choice rather than a mental disorder are flourishing on the Internet.
And doctors and nutritionists are appalled.
"These sites are horrific," says Lauren Solotar, vice president of clinical services and operations at the May Institute in Walpole, Mass., which specializes in behavioral health care, education and rehabilitation.
"These are people who have a disorder who are rationalizing it. It is very dangerous," Solotar says.
Experts say the sites, some of which include message boards and chat rooms, probably wouldn't cause the average person to develop an eating disorder. But they could trigger the irrational fear of becoming fat in someone prone to it.
And the sites can certainly worsen an eating disorder in people who already have one by giving them the "how-to" tips on starvation, and by convincing them their warped perceptions of food and body image are shared by many.
"What everyone else --- friends and family -- are saying is abnormal or unhealthy, these Web sites are promoting and normalizing," says Molly Kimball, a nutritionist at the Ochsner Clinic Foundation in New Orleans. "The sites tell them they're being strong for making the decision not to eat."
An estimated 7 million women and 1 million men in the United States have an eating disorder, according to the National Association of Anorexia Nervosa and Associated Disorders (ANAD).
Complications can include hair loss, weakened bones, gastrointestinal problems, kidney failure, heart attack -- even death.
Eighty-six percent of eating disorders occur before the victim turns 20. And unless the problem is caught early, which happens all too infrequently, the treatment, including therapy and medical monitoring, can be lengthy -- two years or more -- and costly -- $100,000 and up, ANAD says.
As anorexics become more and more obsessive about avoiding food, they often start to isolate themselves from friends and family. The Web forums provide them with an online community of other people with an eating disorder. They provide one another with support -- by telling them that starving themselves is OK.
Consider this posting on one site from a woman who called herself "Emma" and wanted to know what to do about dizzy spells prompted by not eating.
"Wicked site, it's really useful!! It's helped me loads with how to cope with hunger and how to be anorexic."
Or this posting from a woman who was giving tips on hiding an eating disorder from a spouse.
"I always do my binges on the days he's working. Then on the days he's not, I stick to salads, or super light meals when I'm around him so I don't have to purge. He thinks that I'm 'cured' and that I'm just eating healthy. He doesn't know that mia/ana is back in my life."
"Mia" is short for bulimia nervosa, the disease in which people binge on food and then force themselves to vomit. "Ana" is short for anorexia nervosa, or self-starvation.
As the anorexic grows thinner and thinner, family and friends will often try to intervene, Kimball says. They'll tell the person they look too skinny and encourage them to eat. The anorexic will often further retreat into secrecy, and many -- no one knows the exact number -- look to the message boards on the pro-anorexia Web sites for validation.
"These sites further alienate them from their friends and family," Kimball says.
Rather than help them recover, the people who run these sites are defiant about their illness. They claim their eating disorder is something they can "turn on and off." Or they simply have more willpower and determination than the rest of us to be thin.
"It is most definitely not a lifestyle choice," says Solotar, who specializes in eating disorders. "It is a very serious disorder that can lead to death. There are many medical and physical complications. There is a high mortality rate."
"The longer they have the belief system -- the intense focus on thinness and the phobia against gaining weight -- the more solidified it becomes and the more difficult it is to treat," Solotar says. "These are sick people and for some of them, the Web sites are making things worse."
So what can parents do to protect their teens from these sites?
Thwarting their impact isn't easy. But Kimball suggests that parents keep computers in the family room or kitchen, rather than a bedroom, so teens can't be secretive about their Web surfing habits.
What To Do
If you or someone you know needs help with anorexia or bulimia, visit the National Association of Anorexia Nervosa and Associated Disorders. There are also numerous sites that offer referrals for treatment and online support, including S.C.a.R.E.D.