Objective: The aims of this study were to determine the prevalence of eating disorders (ED) in a representative school population of early adolescents of both sexes and to evaluate persistence and incidence after two years.
Method: An initial sample of 1336 (mean age = 11.37) was assessed in a two-phase design. The Children Eating Attitudes Test was used to select 258 participants (T1) from the initial sample who were followed-up two years later (T2; n = 200). Diagnoses of ED were obtained using the Diagnostic Interview for Children and Adolescents- Children and Parent Version (DICA-C and DICA-P) at T1, and Adolescent Version (DICA-A) at T2. At T2, participants were also assessed with the Eating Attitudes Test, the Bulimic Investigatory Test, and the Eating Disorders Inventory. The Body mass index (BMI) was obtained for all participants.
Results: The estimated prevalence of any ED according to DICA-C (T1) and DICA-A was 3.44% and 3.81%, respectively. The most frequent diagnoses were syndromes that were not full-blown. Biannual incidence of any ED was 2.02%. Amongst those with an ED, 52.17% persisted. Females showed a higher incidence and persistence of any ED than males. Participants who had the highest BMI were those who had a persistent diagnosis of ED.
Conclusion: ED that began at early ages in less severe forms and in females often persisted with increasing severity.