Interventions for insulin omission for weight loss in people with type 1 diabetes without a clinical eating disorder: a systematic review

Objective: The aim of this systematic review was to assess interventions treating insulin restriction for weight loss as a disordered eating behaviour independent of clinical eating disorders.Methods: Eligible studies recruited patients with type 1 diabetes restricting insulin for weight loss with no clinical eating disorder. They employed a randomised controlled trial design to deliver interventions that treated insulin restriction for weight loss and measured this behaviour pre and post-intervention. A total of 15 medical, psychological and social databases, registers and websites were searched for evidence including grey literature up to March 2023.Results: This systematic review found no RCT that met the initial eligibility criteria from 1065 records, despite 17 full texts screened and five ongoing trials. The most common reasons for exclusion at full text were the design and absence of or inability to isolate a measure of insulin manipulation for weight loss. Following existing examples of empty systematic reviews and other official guidance, measurements for insulin manipulation were discussed, and four studies were evaluated for secondary outcomes of glycaemic control and psychological wellbeing.Conclusions: Cohort studies with people restricting insulin for weight loss suggest that psychoeducation may not be an effective method for intervention. However, an updated review should be conducted following the completion of the clinical trials mentioned. Future research should seek to standardise a measurement and screening tool for the restriction of insulin for weight control, and further explore the experiential aspects of the phenomenon to help direct intervention and recommendation for clinical guidelines.