The impact of low-energy total diet replacement with behavioural support for remission of type 2 diabetes on disordered eating (ARIADNE): Protocol for a non-inferiority randomised controlled trial

Introduction: The National Health Service (NHS) in England is currently piloting a weight loss programme for remission of newly diagnosed type 2 diabetes (T2D), where participants replace all food with low-energy nutritionally complete formula products for 12 weeks (total diet replacement, TDR) and receive behavioural support. In a clinical trial, this programme led to remission in nearly half the participants. However, this weight loss programme might also worsen disordered eating and prompt eating disorders in susceptible people. We aim to investigate if the TDR programme is non-inferior to standard care in terms of disordered eating in susceptible individuals. Methods: Fifty six people with newly diagnosed T2D, BMI ≥ 27 kg/m2, and medium to high scores of disordered eating based on the Eating Disorders Examination questionnaire (EDE-Q) will be randomised 1:1 to TDR receiving remote weekly/bi-weekly dietetic support or standard care. Participants will be re-assessed remotely at 1, 3, 4, 6, and 12 months. The primary outcome will be the between-group difference in the score of the EDE-Q. If the sample size can be expanded to 150, we will reduce the non-inferiority boundary. Weight, glycated haemoglobin (HbA1c), impairment from disordered eating, and distress will be secondary outcomes. Using the recorded consultations, we will evaluate the process in observed changes in eating behaviour and disordered eating. Conclusions: If TDR for T2D remission is deemed non-inferior to standard care, more people may enrol and benefit from T2D remission. If TDR exacerbates disordered eating, screening may reduce unintended harm. Trial Registration: NCT05744232 (ClinicalTrials.gov, prospectively registered).