The recent recognition of type 5 diabetes—also known as malnutrition-related diabetes mellitus (MRDM)— a fifth diabetes classification alongside types 1, 2, 3c (pancreatogenic), and gestational diabetes, reflects its distinct pathophysiology and its prevalence in low- and middle-income countries (LMICs), mainly in South-East Asia and sub-Saharan Africa.
Although type 5 diabetes has been on the radar for over 70 years, it has fallen through the cracks of the global health system. The condition was first noted in the mid-20th century and often misclassified as type 1 or 2 diabetes due to overlapping symptoms and the absence of formal diagnostic criteria. In 1985, the World Health Organization (WHO) recognised malnutrition-related diabetes as a distinct condition. Still, it later removed this designation in 1999 due to a lack of follow-up studies and supporting evidence.
In January 2025, an international panel of diabetes experts met in India and unanimously voted to classify malnutrition-related diabetes as “type 5 diabetes”. This decision was later endorsed at the International Diabetes Federation (IDF) World Diabetes Congress held in Bangkok in April 2025, where IDF officially recognised this long-overlooked form of diabetes.
Although type 5 diabetes has been on the radar for over 70 years, it has fallen through the cracks of the global health system.
This new diabetes classification refers to severe insulin-deficient diabetes (SIDD), characterised by high insulin deficiency levels and fluctuating blood glucose levels. Researchers believe it starts with poor nutrition over time, which can affect how the pancreas develops and how well it works later in life. In contrast, type 1 diabetes results from the autoimmune destruction of insulin-producing cells, while type 2 diabetes presents in the body’s inability to use the insulin it produces.
Similar to type 1 diabetes, type 5 diabetes often presents in younger people with symptoms such as weight loss and elevated blood glucose. However, unlike people with type 1, it does not involve autoimmune destruction of pancreatic β-cells. While it is non-autoimmune and not always insulin-dependent, like type 2 diabetes, type 5 differs in that it primarily affects undernourished people rather than those living with obesity.
Until recently, no standardised criteria existed to recognise or distinguish type 5 diabetes, leading to a default classification into the more familiar type 1 or type 2 categories. In LMICs, where access to advanced diagnostic tools and endocrinologists is limited, nuanced classification is often unfeasible, further increasing the risk of misdiagnosis.
This long-overdue official recognition of type 5 diabetes enriches our understanding of the broader diabetes landscape and the health disparities within it.
The global burden of diabetes is accelerating, with new data from the 11th edition of the IDF Diabetes Atlas estimating that some of the steepest increases are expected in Africa and South-East Asia, where type 5 diabetes is most prevalent and the rates of malnutrition and undernourishment are highest. India alone now presents over 101 million people with diabetes. Against this increase, we have seen the emergence of phenotypes that help us understand how the condition develops for early intervention or even prevention.
So why does type 5 diabetes disproportionately affect people in LMICs? The roots lie in the lasting consequences of deprivation. Disease, poor maternal nutrition and chronic food insecurity disrupt early metabolic development, setting the stage for diabetes later in life. Among children and adolescents in these regions, prolonged undernutrition can impair the development of the pancreas and weaken the body’s ability to produce insulin—factors that increase the risk of developing the condition.
The Global Diabetes Institute estimates that type 5 diabetes affects 20 to 25 million people worldwide, primarily in sub-Saharan Africa, South-East Asia (India, Bangladesh and Nepal), and parts of Western Pacific and Latin America. The condition affects adolescents and young adults, often presenting a body mass index (BMI) below 19 kg/m². Contrary to risk factors for other types of diabetes, it is not associated with obesity or sedentary lifestyles.
While type 5 diabetes is often associated with LMICs, it may also pose a risk in low-resource settings within high-income countries. In many such communities, food insecurity, housing instability and limited access to nutritious food exist, leading to chronic undernutrition, particularly among children. Moreover, health disparities in under-resourced healthcare systems may result in misdiagnosis or complete oversight of atypical diabetes presentations, including type 5.
An additional at-risk population is refugees, asylum seekers and migrants who experienced childhood undernutrition. They may unknowingly carry this risk into adulthood, even after resettling in high-income countries.
Disease, poor maternal nutrition and chronic food insecurity disrupt early metabolic development, setting the stage for diabetes later in life.
Early diagnosis and intervention underpin the prevention of complications. Following a diagnosis, managing type 5 diabetes requires a tailored approach, as standard insulin therapy is not always sufficient. Instead, treatment strategies should prioritise improving overall health and nutrition to support insulin production. Insulin in low doses or oral agents can be included in treatment plans. However, these do not work equally well for everyone.
Misdiagnosis has placed many people with type 5 diabetes on inadequate and potentially harmful treatment paths. Often mistaken for more common forms of the condition, they are routinely started on insulin or oral agents. These therapies do not address the root problem: a severe insulin secretion defect driven by long-term malnutrition. These drugs can trigger dangerously low blood glucose or may not fully help manage blood glucose levels. Often, life expectancy is a little more than a year following a type 5 diagnosis.
As type 5 diabetes is closely tied to undernutrition, people who are misdiagnosed rarely receive the nutritional and metabolic support they need. This results in many experiencing worsening muscle loss and further damage to pancreatic function. Misdiagnosis can also lead to frustration, depression and a growing loss of trust in healthcare providers, especially when treatments fail and symptoms persist or worsen.
Misdiagnosis has placed many people with type 5 diabetes on inadequate and potentially harmful treatment paths.
The absence of a tailored treatment strategy not only undermines day-to-day management but also increases the risk of early disability or premature death. Poor glycaemic control accelerates complications such as retinopathy, nerve damage and kidney disease—consequences that could be mitigated with the correct diagnosis and care.
Given its unique pathophysiology, standard treatments for type 1 or type 2 diabetes may not work. Research suggests that therapies that improve insulin secretion and nutritional status could provide better health outcomes. However, for now, further studies are needed to establish evidence-based treatment plans.
With the recognition of type 5 diabetes comes the need to develop specific treatment guidelines. Together with this recognition at the IDF World Diabetes Congress 2025 came the announcement of a new working group, the Type 5 Diabetes Working Group, co-chaired by Dr Meredith Hawkins of the Albert Einstein College of Medicine and Dr Nihal Thomas of Christian Medical College in India. This group will draft formal diagnostic criteria and therapeutic guidelines over the next two years. Their aims include:
This IDF Working Group paves the way for much-needed progress: the development of accurate diagnostic criteria, evidence-based treatment strategies and context-specific education for healthcare providers.
This IDF Working Group paves the way for much-needed progress: the development of accurate diagnostic criteria, evidence-based treatment strategies and context-specific education for HCPs.
This long-overdue official recognition of type 5 diabetes enriches our understanding of the broader diabetes landscape and the health disparities within it. By acknowledging the distinct pathophysiology of type 5 diabetes and the social determinants driving its emergence, the medical community is taking up the interrupted journey toward addressing a long-neglected condition affecting millions in under-resourced regions. Formal diagnostic criteria, targeted treatment strategies and region-specific education programmes will contribute to eliminating misdiagnosis, improving health outcomes for millions and strengthening healthcare systems. As we anticipate rising diabetes rates, integrating type 5 diabetes into the global diabetes agenda is not only overdue, it is imperative.
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