Pictures of jutting bones, concave stomachs and toothpick thighs are sprinkled throughout a handful of boards on the visually-driven social networking site Pinterest, providing "thinspiration" for men and women with eating disorders.
Slogans meant to encourage people in the grips of an eating disorder, such as "Whatever you eat in private, you wear in public" and "Make them regret the day they dare called you fat" are printed in fun fonts atop lean, stick-thin bodies.
"It provides community in all the wrong ways. It only seeks to keep people entrenched in self-destructive behavior," Claire Mysko, coordinator of the National Eating Disorder Association's Proud2beme website, told ABCNews.com.
Mysko and NEDA reached out to blogging site Tumblr last month and worked with the company to ban pro-eating-disorder content. Last year, they worked with Facebook. Mysko said she hopes Pinterest will follow suit.
A spokesperson for Pinterest told ABCNews.com they are looking into the issue and their acceptable use policy in order to determine the best course of action.
The pro-anorexia and pro-bulimia movements, called pro-ana and pro-mia for short, have been on the Web for more than a decade, providing encouragement to men and women who have eating disorders to continue on a path of unhealthy behaviors.
"We are definitely seeing more content on these more mainstream platforms," Mysko said.
Caitlin Boyle, a healthy-living blogger and author of the book "Operation Beautiful," called the messages of the pro-eating disorder movement "thought influencers."
"The thing I have noticed with these thinspiration sites is it really normalizes distorted behavior," she said. "It makes the viewer of this content believe their behavior is O.K. and acceptable."
Boyle started a viral campaign, Operation Beautiful, nearly three years ago to spread positive messages. Since then, anonymous people have sent her pictures of more than 10,000 simple sticky notes in public places spreading life- and body-affirming messages. She said she'd like to see healthier messages prevail on Pinterest and other sites.
"When people view social media sites that are positive, it encourages them to think more like that, even when they leave the site," she said. "It can have a positive effect on their self-esteem."