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.

The REAL 2.0 cohort achieved a 30.4% follow-up completion rate from those who consented to be re-contacted.

• The original cross-sectional REAL study surveyed 3,043 middle and high school students from 2004 to 2010 across 43 schools in the Ottawa, Canada region.
• Of those, 1,197 participants from 25 of the 43 original schools were enrolled in a longitudinal arm with yearly follow-ups.
• From the longitudinal cohort, 912 participants consented to be re-contacted.
• 278 participants completed the REAL 2.0 survey electronically (30.4% of those re-contacted).
• The follow-up sample was 29.1% male with a mean age of 28.6 years.

9.4% of REAL 2.0 participants met DSM-5 criteria for an eating disorder in early adulthood.

• An additional 17.6% met criteria for disordered eating, which did not meet full DSM-5 diagnostic thresholds.
• These findings emerged from a sample of 278 participants originally recruited as adolescents in grades 7 or 9.
• The study was specifically designed to investigate how early etiological factors including body image and disordered eating symptoms in adolescence contribute to eating and weight-related concerns in adulthood.

Moderate to severe anxiety was reported by 28% of REAL 2.0 participants in early adulthood.

• 21.6% of participants experienced moderate to severe depressive symptoms.
• These mental health outcomes were assessed in a sample of 278 participants with a mean age of 28.6 years.
• The study was designed to examine how psychosocial risk and protective factors in adolescence shape mental health outcomes in adulthood.

Substantial rates of hazardous substance use were observed in the REAL 2.0 adult cohort.

• 16.9% of participants engaged in hazardous drinking.
• 16.9% used cannabis daily or almost daily.
• 4.3% reported daily tobacco use.
• These substance use findings were collected as part of comprehensive data on demographic, clinical, psychological, social, environmental, and substance use health factors in adulthood.

The REAL 2.0 study is designed to investigate multimorbidity and its risk and protective factors as a priority research focus.

• The study covers a 15-year follow-up period from early adolescence to early adulthood.
• Secondary goals include profiling work linked to health service utilisation data for systems planning and predictive modelling studies.
• The study leverages the Health Data Nexus (HDN) platform to enable collaboration with interested researchers.
• Future plans to conduct additional follow-ups beyond the current 15-year window were noted as feasible.
• The cohort provides data on eating and weight-related behaviour, psychological, social, environmental, and substance use health factors in both adolescence and adulthood.