The ACTyourCHANGE in Teens Study Protocol: An Acceptance and Commitment Therapy-Based Intervention for Adolescents with Obesity: A Randomized Controlled Trial

This Randomized Controlled Trial [(RCT) aims to evaluate the effectiveness of a brief Acceptance and Commitment Therapy (ACT)-based intervention combined with treatment as usual (TAU) compared to TAU only in improving psychological conditions in a sample of adolescents with obesity (body mass index, BMI > 97th percentile for age and sex) within the context of a wider multidisciplinary rehabilitation program for weight loss. Fifty consecutive adolescents (12-17 years) of both genders with obesity will be recruited among the patients hospitalized in a clinical center for obesity rehabilitation and randomly allocated into two experimental conditions: ACT + TAU vs. TAU only. Both groups will attend a three-week in-hospital multidisciplinary rehabilitation program for weight loss. The ACT + TAU condition comprises a psychological intervention based on ACT combined with a standard psychological assessment and support to the hospitalization. The TAU comprises the standard psychological assessment and support to the hospitalization. At pre- to post-psychological intervention, participants will complete the Avoidance and Fusion Questionnaire for Youth, the Psychological Well-Being Scale, the Depression Anxiety Stress Scale, the Difficulties in Emotion Regulation Scale, and the Emotional Eating subscale of the Dutch Eating Behavior Questionnaire to assess psychological well-being as the primary outcome and experiential avoidance, psychological distress, emotional dysregulation, and emotional eating as secondary outcomes. Repeated-measures ANOVAs (2 x 2) will be conducted. The study will assess the effectiveness of a brief ACT-based intervention for adolescents with obesity in improving their psychological conditions by targeting specific core processes of the ACT framework (openness, awareness, and engagement). Future directions of the study will assess whether these psychological processes will contribute to addressing long-term weight loss.