Experts urge formal recognition of Type 5 diabetes, a neglected condition affecting undernourished youths
Lancet Global Health study calls for international action and research into a largely unrecognized form of diabetes believed to affect millions
A team of researchers is pressing health authorities to formally recognise a neglected form of diabetes believed to affect millions of young, underweight people worldwide. In a Lancet Global Health paper published this week, about 50 scientists from 11 countries argue that Type 5 diabetes—also described as malnutrition-related diabetes mellitus or a variant of MODY (maturity onset diabetes of the young)—is a distinct condition that warrants targeted research and treatment guidelines.
The authors say the condition is closely linked to insufficient food intake and typically emerges in teenagers and young adults who are underweight or who faced severe food insecurity during childhood. They caution that Type 5 diabetes is underdiagnosed and may be mismanaged because there are no widely accepted, evidence-based treatment guidelines. The paper emphasizes that recognizing Type 5 could significantly affect the quality and length of life for millions of people worldwide. “We call upon the international diabetes community to recognise this distinct form of the disease,” the researchers write, adding that it is believed to affect up to 25 million people globally and may be overlooked in many settings. They also urge international bodies such as the International Diabetes Federation and the World Health Organization to advance research into the phenotype, pathophysiology and treatment of Type 5 diabetes.
"Misdiagnosis and underdiagnosis are likely to have negatively impacted the clinical care and lives of millions of individuals worldwide," the report notes. Dr Allan Vaag, a professor of endocrinology at Lund University in Sweden and one of the paper’s co-authors, said, “We simply don’t know how many of these patients exist. They live in some of the most underserved and understudied regions, areas affected by natural disasters, war, and famine. These individuals are often among the poorest in the world, making their needs even more critical.”
Experts say Type 5 diabetes is a distinct condition in its own right: people with this form can produce insulin and are not insulin resistant, but their pancreas is underdeveloped and cannot make enough insulin. Consequently, treating Type 5 as if it were Type 1 or Type 2 can be ineffective or even harmful. Researchers have suggested dietary adjustments to help manage the condition, including higher intakes of protein and complex carbohydrates—such as lentils, legumes and whole grains—and a diet rich in fiber, which can slow carbohydrate digestion and reduce blood-sugar spikes after meals.
The work arrives amid broader context about the global burden of diabetes. Type 1 diabetes is an autoimmune condition in which the pancreas fails to produce insulin, while Type 2 diabetes arises when the body does not make enough insulin or cannot use it effectively. Type 5 is not tied to lifestyle in the same way as Type 2 and, unlike Type 1, the insulin-producing cells are present but insufficiently developed. The authors note that recognition and understanding of Type 5 have lagged behind other forms, contributing to potential delays in diagnosis and appropriate care.
Historically, the term first appeared in Jamaica in 1955. Three decades later, the World Health Organization classified “malnutrition-related diabetes mellitus” as a distinct diabetes type. The category was dropped in 1999 due to limited evidence at the time. Today, Type 5 is still largely unrecognised in clinical guidelines, which can hinder screening, diagnosis and treatment in regions most affected by poverty, food insecurity and malnutrition.
Within the United Kingdom, diabetes remains a major public health challenge. Roughly 4.3 million people were living with diabetes in 2021/22, according to Diabetes UK, with about 850,000 people unaware they have the disease. While Type 5 would add to the global burden, experts say its recognition would not only illuminate a hidden condition but also prompt more comprehensive care for populations already at high risk for diabetes-related complications, including heart, kidney and nerve disease.
The Lancet Global Health paper concludes with a call to action for international organisations and national health systems to prioritise research into Type 5 diabetes, establish clear diagnostic criteria, and develop tailored treatment protocols. In the authors’ view, doing so could improve outcomes for millions of people who are currently underserved and at risk of an avoidable impact on health and longevity.