The International Diabetes Federation, a global alliance of over 250 national diabetes associations from more than 160 countries and territories, has formally recognized a fifth form of diabetes. A consensus meeting held in January 2025 in India proposed type 5 diabetes as the nomenclature, and this was subsequently formalized during the World Diabetes Congress in April 2025.
The International Diabetes Federation Officially Recognized of Type 5 Diabetes as a Distinct Clinical Entity
An alliance of diabetes authorities around the world has officially recognized Type 5 diabetes, a malnutrition-associated condition, and has underscored its distinction from existing diabetes categories. The decision acknowledges decades of evidence showing that chronic undernutrition can permanently impair insulin production.
Background
Type 5 diabetes, also called malnutrition-related diabetes mellitus, is a distinct form of diabetes emerging from long-term undernutrition, especially during childhood, thus leading to insufficient insulin production due to impaired pancreatic development, not autoimmunity or type 1 diabetes mellitus or insulin resistance or type 2 diabetes mellitus.
It was in 1955 when this type of diabetes was first observed and described among lean and young individuals in Jamaica. The World Health Organization briefly acknowledged it in the 1980s but later withdrew the classification in 1999 due to a lack of evidence and diagnostic uncertainty. The condition was then sidelined by researchers and doctors.
Type 5 diabetes has been rarely discussed or researched since then. Clinicians either misdiagnosed it or assumed it was one of the already known types. But data indicate that up to 25 million people worldwide may have this form of diabetes. This is true in low-income and middle-income countries where malnutrition and food insecurity are widespread.
Nevertheless, as a consequence of the decision of the International Diabetes Federation, the formal and official recognition of this fifth type of diabetes has critical implications for global health. This addresses the issues of patients receiving incorrect treatment protocols, the absence of official tracking data, and minimal research funding or focus.
Descriptions
Remember that type 5 diabetes is also called malnutrition-related diabetes mellitus. Hence, unlike other types of diabetes, it does not stem from autoimmunity, lifestyle-related insulin resistance, damage to the pancreas, or pregnancy-related hormone changes. Researchers believe that it results from long-term malnutrition during early development.
The emerging consensus is that prolonged nutrient deficiency leads to poor or arrested pancreatic development. This results in the pancreas having reduced ability to produce enough insulin. The pathophysiology of type 5 diabetes or malnutrition-related diabetes points to a different disease mechanism compared to other categories of diabetes mellitus.
Individuals with malnutrition-related diabetes mellitus tend to be lean or underweight. They do not feature the typical obesity or insulin resistance seen in type 2 diabetes. These individuals also have some insulin production, but not enough to maintain normal blood glucose levels. Their insulin sensitivity is preserved, and they are not insulin resistant.
Hence, considering their unique metabolic profile, misdiagnosing their condition as other forms of diabetes can be detrimental. Conventional treatments for type 2 diabetes, which target insulin resistance, may not work for them. Insulin regimens used in type 1 may even be dangerous for undernourished patients when food access is inconsistent.
Implications
Type 5 diabetes appears most often in Asia and Africa, where childhood undernutrition remains common, often due to poverty, food insecurity, and lack of healthcare access. Experts have further noted that undernutrition-related diabetes is increasingly recognized in Latin America and the Caribbean, tied to worsening socio-economic conditions.
Nevertheless, as part of their formal recognition, the International Diabetes Foundation has created the Type 5 Diabetes Working Group. This group is tasked with developing formal diagnostic criteria, treatment guidelines, global research registries, and relevant training resources to assist clinicians in accurately diagnosing and managing type 5 diabetes.
But not all researchers agree that the classification is ready. Some scientists raise concerns that the data and other evidence are not complete. There is diagnostic uncertainty because malnutrition-related diabetes cases vary widely. These experts believe that More data is needed to fully understand and define the clinical features and best treatment approaches.
The formal recognition by the International Diabetes Foundation is still intended to restart further discussion, research, and consensus related to malnutrition-related diabetes mellitus. It also helps in reiterating that diabetes mellitus is a spectrum of disorders with multiple biological causes requiring different treatments and public health strategies.
FURTHER READING AND REFERENCE
- Wadivkar, P., Jebasingh, F., Thomas, N., Yajnik, C. S., Vaag, A. A., Kibirige, D., Bahendeka, S., Bajaj, M., Boyne, M. S., Bavuma, C., Abodo, J., Wild, S., Kolthur-Seetharam, U., Mukhopadhyay, S., Somasundaram, N. P., Schwarz, P., Christensen, D. L., Pathan, F., Jones, A. G., … Yajnik, C. 2025. “Classifying a Distinct Form of Diabetes in Lean Individuals With a History of Undernutrition: An International Consensus Statement.” The Lancet Global Health. 13(10): e1771–e1776. DOI: 1016/s2214-109x(25)00263-3