In April 2025, the International Diabetes Federation (IDF) officially acknowledged type 5 diabetes, also known as malnutrition-related diabetes, as a distinct form of diabetes during the World Diabetes Congress. This recognition has sparked a significant debate globally, especially as the World Health Organization (WHO) has not yet followed suit. The controversy primarily lies in scientific uncertainty regarding the disease, challenges in diagnosis, and differing views on the role of malnutrition in diabetes development. Approximately 20-25 million people worldwide may be impacted by this condition, according to the IDF, emphasizing the need for awareness and action. Type 5 diabetes, which often presents during youth or young adulthood, is characterized by severe insulin deficiency without insulin resistance, a unique profile that distinguishes it from type 1 and type 2 diabetes. The condition is typically linked to a history of significant nutritional deprivation. Originally identified in Jamaica during the 1950s as “J-type diabetes” and later termed malnutrition-related diabetes mellitus, its classification has evolved over the years, with the WHO initially recognizing it in 1985 before removing it from their classification in 1999 due to insufficient evidence. Three main critiques have fueled skepticism about type 5 diabetes, as noted in an editorial from the journal Biochimica et Biophysica Acta (BBA). These critiques include the debate over whether malnutrition leads to or results from diabetes, the questionable reliability of BMI as a marker for malnutrition, and the diagnostic ambiguity that overlaps with other diabetes forms. As a result of these challenges, the IDF has set up a specialized working group focused on creating standardized diagnostic criteria and treatment recommendations specifically tailored to type 5 diabetes. Dr. Meredith Hawkins, chair of the IDF Type 5 Diabetes Working Group, has been vocal about the significance of recognizing this condition, comparing its prevalence to that of tuberculosis and stating that the lack of a formal name has obstructed efforts to identify patients and develop effective therapies. The aim is that the formal acknowledgment of type 5 diabetes will enhance global action and facilitate necessary funding for better diagnosis and treatment in regions suffering from chronic undernutrition. Future discussions between health authorities such as the WHO and the IDF could lead to a consensus on the classification of type 5 diabetes, depending on the emerging clinical and epidemiological data.