ARFID InitiativE Sweden (ARIES): study protocol for a large-scale genetic and registry-linked cohort study on avoidant/restrictive food intake disorder.

Abstract

The ARFID InitiativE Sweden (ARIES) investigates the genetic and environmental factors contributing to avoidant/restrictive food intake disorder (ARFID) in children and adolescents aged 6-14 years. ARIES will establish a national biobank and research registry. It aims to provide data for immediate research and track ARFID outcomes and clarify genetic links between ARFID and other conditions and analyse the gut microbiome to guide nutrition interventions. The study will involve 1500 Swedish children and adolescents with ARFID and a control group of 500 Swedish children and adolescents without ARFID. Parents/guardians and their children will complete online questionnaires assessing ARFID and other eating disorder (ED) pathology, co-occurring conditions, quality of life and parental stress and ED pathology. All participants will provide a saliva sample for comprehensive genetic analyses. Additionally, a subset of participants will provide a stool sample to investigate the gut microbiome in ARFID. ARIES was approved by the Swedish Ethical Review Authority (Dnr 2023-04638). All participants will give assent and their parents will complete informed consent. Data will be made available by the authors on reasonable request. Findings will be published in scientific journals and shared with the public and stakeholders in accessible ways, for example, via social media.