Most people think of diabetes as a two-lane road: type 1 or type 2. But in reality, it’s more like a network of winding paths some well-known, others barely marked. And now, one of those long-overlooked paths has finally been given a name.
The International Diabetes Federation has officially recognized a fifth type of diabetes one that doesn’t stem from autoimmunity, obesity, or genetics. Instead, it starts much earlier. Sometimes before a person is even born.
Type 5 diabetes is rooted in malnutrition during early development. It affects an estimated 25 million people worldwide, most of them young and lean, often living in low-income regions where food insecurity is common. It’s not new cases were documented as far back as the 1950s but until now, it’s been misclassified, mistreated, and largely ignored.
This reclassification isn’t just a bureaucratic update. It changes how we think about diabetes, nutrition, and the long-term consequences of early-life adversity. Here’s what sets Type 5 apart and why it matters more than ever.
Diabetes Is Not One Disease
For decades, most people lumped diabetes into just two categories: type 1, often diagnosed in children, and type 2, more common in adults and often linked to weight or lifestyle. But that simplified view has quietly collapsed under the weight of decades of research. Diabetes isn’t one disease it’s a collection of conditions that all result in high blood sugar, but for very different reasons.
Type 1 diabetes is autoimmune. The body attacks its own pancreas, destroying insulin-producing beta cells. It can happen at any age and has nothing to do with diet or exercise. People with type 1 require lifelong insulin therapy usually through injections or a pump. In rare cases, they may undergo islet cell transplants or experimental stem-cell treatments, but those remain limited in availability and accessibility.
Type 2 diabetes is more common and often misunderstood. While it’s strongly associated with excess weight, especially abdominal fat, that’s not the whole story. Many people with type 2 are of normal weight, particularly in certain ethnic groups. Type 2 happens when the body doesn’t use insulin effectively (insulin resistance), doesn’t produce enough of it or both. It’s treated with medications like metformin, and in some cases, intensive lifestyle changes or low-calorie diets can lead to remission.
Then there’s gestational diabetes, which arises during pregnancy, and typically resolves afterward though it raises the long-term risk of developing type 2. Beyond these familiar types are several lesser-known but well-documented forms:
- MODY (Maturity-Onset Diabetes of the Young): a genetic form usually appearing in teens or young adults.
- Neonatal diabetes: appears in infants, often due to specific gene mutations.
- Type 3c diabetes: caused by direct damage to the pancreas from diseases like pancreatitis or pancreatic cancer.
- Cystic fibrosis-related diabetes: common in people with cystic fibrosis due to progressive pancreatic damage.
All of these share the same end result chronically elevated blood sugar but the causes are as different as a broken thermostat vs. a faulty power line. Misclassifying one type as another doesn’t just delay treatment it can actively cause harm.
What Makes Type 5 Diabetes Different
Type 5 diabetes doesn’t fit the mold. It doesn’t involve an autoimmune attack like type 1, and it’s not driven by insulin resistance tied to body weight, as in type 2. Instead, this form of diabetes begins with a very different problem: undernutrition during early development sometimes as early as the womb.
When a child doesn’t get enough protein or essential nutrients during critical growth periods, the pancreas may not fully develop. That includes the beta cells responsible for producing insulin. The result? A permanently reduced ability to make insulin, even in the absence of obesity, genetic risk, or autoimmune damage. The person may appear lean and healthy, but their pancreas is functioning at half-capacity or worse.
This condition mostly shows up in teenagers and young adults who are chronically undernourished. It’s been reported in countries across South Asia and sub-Saharan Africa, where food insecurity is widespread, but it’s also been seen in low-income or food-insecure communities elsewhere. According to Dr. Meredith Hawkins, director of the Global Diabetes Institute, U.S. children in foster care or migrants who experienced early food scarcity could also be affected though often misdiagnosed.
What makes Type 5 particularly dangerous is that it often looks like type 1 or type 2 diabetes from the outside, but it behaves differently on the inside. People may need only small amounts of insulin or oral medication. Standard doses, especially if misapplied based on a type 1 or 2 assumption, can drive blood sugar dangerously low. In some reported cases, this has led to life-threatening complications.
There’s also no specific blood test to identify Type 5. Diagnosis relies on recognizing a pattern: low BMI (typically under 18.5), very low insulin levels, no evidence of autoimmunity, and a history of malnutrition. These clues point to a pancreas that never had the chance to fully develop, not one that’s been attacked or burned out over time.
Why This Recognition Took So Long
Type 5 diabetes may be new to the official record, but it’s not new to science. The condition was first described in 1955 in Jamaica under the term “J-type diabetes.” By 1985, the World Health Organization acknowledged it under the label “malnutrition-related diabetes mellitus.” Yet in 1999, that classification was quietly dropped not because the disease had disappeared, but because global consensus on its cause hadn’t been reached.
At the time, there wasn’t enough hard data to prove that malnutrition alone could cause permanent damage to insulin production. Some thought these cases were simply atypical presentations of type 1 or type 2 diabetes. With limited research infrastructure in affected regions, and an overwhelming focus on obesity-driven diabetes in high-income countries, the condition slipped through the cracks.
But clinicians on the ground especially in South Asia and Africa kept seeing patients who didn’t fit any known pattern. Dr. Meredith Hawkins recalls treating young, underweight patients whose diabetes didn’t respond to typical treatments. Standard insulin doses caused severe hypoglycemia. Many didn’t have the autoantibodies seen in type 1, nor the insulin resistance seen in type 2. Something else was going on.
It took years of careful research to connect the dots. Animal studies eventually showed that protein-deficient diets during pregnancy and early childhood could permanently impair pancreatic development. Human data followed, and recent research confirmed a clear link: children who experience undernutrition early in life are at higher risk of developing a unique form of diabetes later on even if they remain lean and eat adequately as adults.
Still, recognition lagged. Until recently, most clinical guidelines didn’t account for diabetes triggered by early-life malnutrition. And because these cases mostly occurred in poorer regions of the world, they were often left out of large, international studies that shape how we define and treat disease.
That changed in January 2025, when the International Diabetes Federation formally named Type 5 diabetes as a distinct condition at its World Congress in Bangkok. According to IDF president Prof. Peter Schwarz, the decision was long overdue. The data finally matched what frontline doctors had been reporting for decades.
Medical classification systems are slow to evolve and slower still when the patients affected have the least political or economic power. The recognition of Type 5 diabetes is not just a scientific update. It’s a long-delayed acknowledgment of a disease that has been misdiagnosed, mismanaged, and largely ignored for nearly 70 years.
Unique Challenges in Diagnosis and Treatment
One of the most pressing issues with Type 5 diabetes is that it’s difficult to identify and even harder to manage using standard tools. Unlike type 1, there are no autoimmune markers. Unlike type 2, insulin resistance isn’t the driving force. That makes Type 5 easy to misclassify and potentially dangerous to treat using conventional protocols.
There’s no single lab test that confirms a Type 5 diagnosis. Instead, diagnosis relies on pattern recognition: low BMI (typically under 18.5), very low body fat, reduced insulin secretion, and a personal history or clinical suspicion of early-life malnutrition. Unlike type 1, insulin is still being made, but in much smaller quantities. And unlike type 2, insulin sensitivity may be intact or even elevated due to a lack of body fat and muscle mass.
This presents serious treatment dilemmas. In type 1 diabetes, the goal is full insulin replacement. In type 2, treatment often involves medications that improve insulin sensitivity or boost insulin production. But in Type 5, the pancreas is underdeveloped not resistant, not destroyed so flooding the body with standard insulin doses can cause blood sugar to drop too low, too fast. That’s not a mild side effect. Severe hypoglycemia can lead to seizures, coma, or death.
Dr. Meredith Hawkins, who’s studied and treated cases of Type 5 in Africa and Asia, observed that many young patients were suffering complications not from their diabetes but from inappropriate treatment. Oral medications and small, carefully dosed amounts of insulin may be effective, but only when tailored to the patient’s unique physiology.
Nutrition therapy is also essential. These patients don’t just need glucose control they need to rebuild lost body mass and support pancreatic function. That means increasing dietary protein, replenishing micronutrients, and ensuring a balanced intake of carbohydrates and fats. But those aren’t easy prescriptions in regions where food insecurity is still a daily reality.
Even in high-income countries, Type 5 may go undetected. Providers may miss it in patients who’ve experienced severe weight loss from eating disorders, bariatric surgery, or extended illness. Though those cases aren’t the classic Type 5 profile, the same pattern reduced muscle mass, lower insulin production, and heightened sensitivity to treatment may apply. As Dr. Rozalina McCoy from the University of Maryland explains, clinicians need to start asking not just about current diet or weight, but about long-term nutritional history.
Practical Takeaways for Readers
You don’t have to be a doctor or global health official to take something useful away from the recognition of Type 5 diabetes. While the condition mostly affects populations in low-income countries, its root causes undernutrition, food insecurity, and poor early-life care aren’t limited to any one region.
Here’s what general readers should keep in mind:
1. Diabetes Isn’t Always About Weight or Sugar
Not everyone with diabetes is overweight, and not everyone who’s thin is in the clear. If you or someone you know has low body weight but shows signs of high blood sugar excessive thirst, fatigue, or unexplained weight loss it’s worth raising the possibility of a nontraditional diabetes type, especially if there’s a history of undernutrition.
2. Early-Life Nutrition Matters Long-Term
If you’re pregnant, planning a family, or caring for young children, early nutrition is critical not just for growth, but for lifelong metabolic health. Ensuring children get enough protein, essential fats, and micronutrients can help their pancreas and other organs develop properly. This isn’t about supplements or trendy superfoods; it’s about meeting basic dietary needs consistently.
3. Extreme Weight Loss Can Disrupt Insulin Function
People who lose a lot of weight quickly whether from illness, bariatric surgery, or certain medications may temporarily resemble some features of Type 5 diabetes. Loss of muscle mass can impair how the body processes glucose. If you’ve experienced rapid weight loss and develop abnormal blood sugar levels, your treatment plan may need to be adjusted to avoid complications.
4. Ask the Right Questions
Healthcare providers in many countries may still be unfamiliar with Type 5 diabetes. If someone is diagnosed with diabetes but doesn’t fit the typical profile for type 1 or 2, ask about their full nutrition history not just recent eating habits, but early-life conditions, past illnesses, and growth patterns.
5. Advocate for Better Food Access, Not Just Better Medicine
Preventing Type 5 diabetes isn’t about high-tech solutions it’s about consistent access to real food. Community-level support for maternal nutrition programs, school feeding initiatives, and policies that reduce child malnutrition are just as important as insulin or glucose monitors.
What Needs to Happen Next
Type 5 diabetes is a reminder that chronic diseases don’t develop in a vacuum. They’re shaped by a lifetime of conditions including ones we don’t choose, like whether we had enough to eat as children or whether our mothers had access to prenatal care. Now that Type 5 has been officially recognized, the question is no longer if it exists, but what are we going to do about it?
There’s urgent work ahead. Health professionals need training to spot this condition early and treat it correctly. Medical systems need diagnostic criteria that don’t default to type 1 or 2. Policymakers need to treat early-life nutrition as a form of chronic disease prevention, not just short-term hunger relief.
But this also comes down to awareness within families, schools, and communities. Recognizing that diabetes isn’t always driven by lifestyle helps remove the stigma, especially in places where thinness is assumed to equal health. It also helps prevent harm when misdiagnosed cases are treated with one-size-fits-all plans that weren’t made for them.
For decades, Type 5 diabetes existed in silence misunderstood, mismanaged, and often unseen. Naming it is only the beginning. Now it’s time to make sure no one living with it gets left behind again.
Sources:
- Van Den Driessche, A., Eenkhoorn, V., Van Gaal, L., & De Block, C. (2009). Type 1 diabetes and autoimmune polyglandular syndrome: a clinical review. PubMed, 67(11), 376–387. https://pubmed.ncbi.nlm.nih.gov/20009114
- Evert, A. B., Boucher, J. L., Cypress, M., Dunbar, S. A., Franz, M. J., Mayer-Davis, E. J., Neumiller, J. J., Nwankwo, R., Verdi, C. L., Urbanski, P., & Yancy, W. S. (2013). Nutrition therapy recommendations for the management of adults with diabetes. Diabetes Care, 36(11), 3821–3842. https://doi.org/10.2337/dc13-2042
