[Anorexia and bulimia nervosa: virtual diffusion of the disease as a lifestyle].

Introduction: Adolescence is a vulnerable period for the onset of eating disorders (ED) such as anorexia and bulimia nervosas. Body dissatisfaction, a precipitating factor for ED, leads adolescents to seek information on the Internet about diets. In this context, pro-Ana (proanorexia) and pro-Mia (probulimia) are on-line pages that promulgate highly harmful contents for health related to weight loss and ED. Objectives: The aim of this study was to analyze quantity, quality and social diffusion strategies used by pro-Ana and pro-Mia webpages. Methods: A web search was done in the Google Chrome browser, using the keywords “anorexia”, “bulimia”, “eating disorders”, “Ana and Mia”, “pro-Ana and pro-Mia”, “anorexic nation”, “obesity”, “healthy lifestyles” and “healthy nutrition”. The top 20 results for each search were selected and analyzed according to positioning rates (PageRank, PR). The quality of these resources was analyzed by a previously published questionnaire. Finally, a study of the diffusion in social networks like Facebook and Twitter was performed for pro-Ana and pro-Mia pages using SharedCount. Results: Searches for pro-Ana and pro-Mia reported more than a million entries. The pages were poorly positioned. Blog contents were the most shared between all the analyzed pages. Conclusions: pro-Ana and pro-Mia are resources with a clear intention to establish a contact with people with an eating disorder or who are at risk for developing one, in order to strengthen the communication through the blogosphere.