BackgroundInsulin restriction and/or omission in Type 1 Diabetes Mellitus (T1DM) is a risky disordered eating behaviour increasingly reported in the literature. Most existing literature has focused on females with T1DM. Previous research, however, suggests disordered eating behaviours are over-represented in males with T1DM versus males without T1DM. This systematic scoping review sought to summarise the existing literature to contribute to the development of an understanding of males’ misuse of insulin for weight and/or shape control.MethodsA systematic scoping review methodology was used. We searched six electronic databases. Eligible articles were quantitative, qualitative, or mixed methods empirical studies with primary data on the restriction and/or omission of insulin for weight and/or shape control among males, written in English from database inception to December 2021.ResultsA final sample of 56 articles was included (48 quantitative, six qualitative and two mixed methods). Where it was reported to occur, estimates of the behaviour ranged from 5 to 75% in females and 1.4% to 76% in males. In 12 studies examining sex differences, only three reported higher prevalence in females. Understandings about the behavioural context of the behaviour were hampered by lack of qualitative research (n = 4 studies).ConclusionDespite common preconceptions, this disordered eating behaviour appears to occur similarly in males and females. The findings shed light on areas for future research, including aetiology in males and the need for longitudinal and qualitative research. Clinical recommendations include being alert to the possibility of this behaviour in males with Type 1 Diabetes Mellitus and the need for health professionals to use open-ended questions to explore current and past deliberate restriction and/or omission of insulin among their patients.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40200-022-01151-8.