Social Media Propagation of Content Promoting Risky Health Behavior.

While social media have been found useful in providing social support and health information, they have also been home to content advocating risky health behavior. This study focused on how content defending and even celebrating anorexia as a lifestyle are circulated among social media users, and investigates the characteristics that promote wide propagation of such messages. We captured anorexia-related content on Tumblr, a popular blog for talking about eating disorders, during a one-month period. Among the 35,432 posts collected, we examined the most highly propagated posts and coded them for message characteristics. Our findings revealed that posts in which the source of a narrative ("testimony") was identified (was either from an anorexic poster or about another's anorexia) and which were positive toward the pro-anorexia perspective were more likely to be propagated on Tumblr. In addition, posts containing content that references an anorexic person and contains an affective tone were more likely to be propagated. We also found that underweight bodies and bodies with a high degree of exposure were associated with propagation of posts. The present study suggested practical implications by focusing on the characteristics of highly propagated but potentially harmful content in social media.