Research on Eating and Adolescent Lifestyle (REAL) 2.0: 15-year follow-up study of eating disorders and weight-related trajectories, mental health and substance use health from early adolescence to early adulthood—a Canadian cohort profile

PURPOSE: Few studies have examined how psychosocial risk and protective factors in adolescence shape mental health outcomes and other multimorbid conditions in adulthood, particularly among Canadian youth. The Research on Eating and Adolescent Lifestyle (REAL) 2.0 study was a 15-year follow-up cohort study designed to investigate how early etiological factors, including body image and disordered eating symptoms in adolescence, contribute to the development of eating, weight-related concerns, mental health and substance use health problems in early adulthood. In this paper, we describe the REAL 2.0 cohort's demographic and clinical characteristics alongside an overview of the study procedures, laying the groundwork for collaboration on future learnings with this unique data. PARTICIPANTS: =28.6) from those who consented to be re-contacted (n=912), who completed the REAL 2.0 survey electronically (30.4%), providing comprehensive data on demographic, clinical, eating and weight-related behaviour, psychological, social, environmental and substance use health factors in adulthood. FINDINGS TO DATE: 9.4% of REAL 2.0 participants met DSM-5 criteria for an eating disorder, while 17.6% met criteria for disordered eating. Moderate to severe anxiety was reported by 28% of participants, while 21.6% experienced moderate to severe depressive symptoms. Regarding substance use, 16.9% engaged in hazardous drinking, 16.9% used cannabis daily or almost daily, and 4.3% reported daily tobacco use. FUTURE PLANS: REAL 2.0 has the potential to answer multiple research questions about several mental health outcomes, but its priority focus is to answer questions related to risk and protective factors of multimorbidity in adulthood. Additionally, profiling work, linked to health service utilisation data for systems planning work and predictive modelling studies are secondary goals. By leveraging the Health Data Nexus (HDN) platform, we welcome collaboration with interested researchers who would like to utilise the breadth of data both in adolescence and adulthood to answer other pertinent aetiological questions in mental health and substance use health outcomes. Future plans to conduct additional follow-ups remain feasible.