Healthy Teens @ School: Evaluating and disseminating transdiagnostic preventive interventions for eating disorders and obesity for adolescents in school settings

Background: The worldwide prevalence of overweight and obesity is at alarming levels. Nearly one in three children in Europe is overweight or obese. Disordered eating and body image concerns are equally widespread and increase risk for more chronic and severe weight-related problems. Research has shown that online interventions that address both healthy weight regulation and body image can reduce risk for eating disorders and obesity simultaneously and are feasible to implement in school settings. To date, evaluation and dissemination of such programs in Europe is scant. Methods: The Healthy Teens @ School study is a multi-country cluster-randomized controlled trial (RCT) comparing the effectiveness of an unguided, online, multi-level intervention for promoting a healthy lifestyle and reducing problematic eating behavior, eating disorder and obesity risk among students aged 14 to 19 years with control condition. As part of the Horizon 2020 funded project ICare (GA No. 634757) the trial is conducted in Austria and Spain. Cluster randomization by school is used. The intervention is an adapted version of an evidence-based program developed in the USA (StayingFit). Participants of the intervention group are assigned to one of two possible program tracks based on the results of the initial online-assessment: Overweight adolescents are assigned to the "Weight Management" track emphasizing balanced eating and exercise for weight maintenance, and all other individuals are assigned to the "Healthy Habits" track which aims at promoting healthy habits related to e.g., nutrition, physical activity, sleep. The participants of both tracks work on ten modules (one 20-30 min module per week) during school hours and/or at home. Assessments are conducted at pre- and post-intervention, and at 6- and 12-months after baseline assessment. The primary outcome is intuitive eating, secondary outcomes are eating disorder symptomatology, body image concerns, body mass index, food intake, physical activity, self-esteem, stress coping, depression, and anxiety. Following the initial assessment, individuals in the control group do not have access to the prevention program but continue as normal and are only prompted to the assessments at all time points. At the end of the 12-month study they will get access to the program. Discussion: The results from this study will add to the understanding of how to address eating and weight related problems in adolescents and will shed light on the feasibility of implementing online prevention programs in school routine in Austria and Spain. As part of the larger ICare project this RCT will determine how an adapted version of StayingFit is disseminated within Europe.