Background <p>Diabetes mellitus affects millions of individuals worldwide and is a major public health concern because of its increasing prevalence and associated complications. Bioelectrical impedance analysis, particularly phase angle, has gained attention worldwide due to its potential as a valuable marker for assessing various aspects of health and disease, including diabetes mellitus.</p> Objective&#xa0; <p>The aim of this study is to explore the implications of phase angle in diagnosis and management of diabetes mellitus.</p> Method <p>Literature search was conducted from PubMed, Scopus, and Google Scholar from the years 2000 to 2024 to obtain studies focussing on those examining phase angle in the context of type 1 and type 2 diabetes mellitus. According to the inclusion and exclusion criteria, two researchers independently screened the literature, extracted data, and evaluated the quality of the included studies. A formal risk of bias assessment was conducted on all included studies. Narrative synthesis was prespecified because of clinical heterogeneity.</p> Results <p>A total of 43 studies were evaluated. Studies show that phase angle can be used as a non-invasive screening tool in diabetes mellitus, as well as improve diagnostic accuracy when used with traditional screening tools. Moreover, lower phase angle indicates poor nutrition and muscle mass, suggesting the need for tailored diet and exercise. A lower phase angle predicts increased risks for diabetes-related complications, as well as higher mortality.</p> Conclusion <p>This study shows that regular phase angle monitoring can aid in early detection of diabetes and related complications, guiding personalized management and improving patient outcomes, in both type 1 and type 2 diabetes mellitus.</p>