AimThe aim of this study was to determine the prevalence of likely eating disorders and insulin misuse in a prospective cohort of adults with type 1 diabetes mellitus (T1DM) treated with insulin pump therapy. MethodsThis prospective study was held at the participants’ home. The participants completed the SCOFF questionnaire as well as a question related to insulin misuse. Information about lifestyle, medical history, insulin pump and Continuous Glucose Monitoring (CGM) data were collected. ResultsThe analysis covered 198 participants with a median age of 51 [95% CI 38; 62] years. The prevalence of likely eating disorders was 21.7% (95% CI 16.3; 28.2) in the study population and 20.6% (95% CI 14.3; 28.6) and 24.2% (95% CI 14.6; 37.0) in males and females respectively. The prevalence of insulin misuse was 39.0% (95% CI 30.8; 47.7). There was no significant difference in prevalence between males and females for likely eating disorders and insulin misuse. The analysis of CGM data revealed no factors related to glycaemic control associated with likely eating disorders. ConclusionThe results of this study indicate that the prevalence of likely eating disorders is high even in a middle-aged population with a T1DM and satisfactory glucose control.