One recent International Journal of Eating Disorders study found that 96 percent of women who have viewed thinspo content reported finding new ways to keep their weight down.
"Social media has become a covert way to share different tricks and tips for managing hunger, restricting calories, self-induced vomiting and ways to hide weight loss," Vazzana said.
Thinspo Bans Prove Tough to Enforce
Even as women -- and a few men -- with disordered eating flock to thinspo sites, a movement is afoot to shut them down. In 2008, France banned websites that promoted an eating disorder lifestyle or that used the hashtags thinspo, pro ana or pro mia. More recently, social sites popular with pro ana groups on this side of the Atlantic have tried similar bans.
But thinspo prohibitions have had limited success. A quick trip through any social site with a purported thinspo ban -- particularly Tumblr, Instagram and Pinterest -- show that content is visible and thriving. When a site is shut down, it simply sets up shop elsewhere.
"It is very difficult to truly eradicate thinspo because of the nature of the Internet," Mysko said. "There are technical limitations and no foolproof way to catch it until after it's been put up. We applaud the platforms that have taken a stand in their community policies, but at the same time we recognize how impossible it is to keep up with it."
For their part, thinspo followers see it as a freedom of speech issue. Why shouldn't they be left to eat, look and live as they please?
But they rarely agree to go on the record. Vazzana said they tend to prefer to remain secretive and anonymous.
"In my 10-plus years of experience in and out of this online community, it is very rare for mainstream media to present an unsensationalized, objective opinion," one thinspo blogger, who asked not to be identified, told ABC News. "Similarly, people who have participated in such reports in the past have been harassed on their accounts and via email."
Mysko said she thought it may be more effective to counteract the thinspo message with positive alternatives.
"We know people struggling with eating disorders and poor body image are looking to connect with others who know what they are going through," she said. "We need to offer a safe, supportive environment that promotes recovery and helps them disengage from an unhealthy mindset."