Diabetes is one of the most common chronic diseases in the world, affecting hundreds of millions of people. For decades, clinicians and scientists have classified diabetes into a handful of main types — with type 1 and type 2 being the best-known. But in 2025, a fundamentally different form of the disease was officially recognized by the International Diabetes Federation (IDF) as a distinct entity called Type 5 diabetes. This recognition reflects decades of scientific debate and new understanding about how chronic undernutrition can shape lifelong metabolic health.
This article explores what Type 5 diabetes is, why recognizing it matters, its causes, symptoms, diagnosis, treatment, and how you might know if you — or someone you care about — has this newly acknowledged condition.
1. Understanding Diabetes: A Brief Overview
To understand what makes Type 5 diabetes unique, it’s important to first review the classic forms of diabetes:
Type 1 Diabetes
Type 1 diabetes is an autoimmune disease — the body’s immune system attacks and destroys the insulin-producing beta cells in the pancreas. People with type 1 produce little or no insulin and require lifelong insulin therapy.
Type 2 Diabetes
Type 2 diabetes is characterized by insulin resistance — where the body’s tissues don’t respond effectively to insulin. It is strongly associated with lifestyle factors like diet, obesity, and inactivity.
Other Recognized Forms
There are forms of diabetes linked to pregnancy (gestational diabetes) and to pancreatic damage (type 3c). There have also been debated categories like type 3 (used informally for diabetes linked to neurological causes), but these have not been formally recognized.
Into this landscape has now come Type 5, a condition that does not fit neatly into previous classifications.
2. What Is Type 5 Diabetes?
Type 5 diabetes, also referred to by researchers as malnutrition-related diabetes mellitus (MRDM), is a form of diabetes that emerges from chronic nutritional deficiency rather than autoimmunity or modern lifestyle factors. In simple terms, it is a diabetes subtype where long-term undernutrition — particularly during childhood — disrupts pancreatic development and function, leading to impaired insulin production.
Unlike type 1, which arises from immune-mediated destruction of beta cells, and type 2, which arises from the body’s resistance to insulin, Type 5 diabetes primarily features reduced insulin secretion due to an underdeveloped or poorly functioning pancreas.
Crucially, Type 5 diabetes often develops in young, lean individuals who have histories of prolonged undernutrition, especially in low- and middle-income regions where food scarcity is common.
This form of diabetes had been described sporadically in medical research for decades and was once recognized (but later removed) by the World Health Organization in the 1980s and 1990s, only to be reinstated and formally named in 2025 by the IDF.
3. The Historical Journey to Recognition
Type 5 diabetes is not an entirely new medical observation; its modern history stretches back to the mid-20th century:
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Researchers in Jamaica first described a form of diabetes in lean, undernourished people as early as the 1950s.
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In 1985, the World Health Organization (WHO) classified a condition called malnutrition-related diabetes mellitus, acknowledging its distinctiveness.
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However, in 1999, this category was removed due to disagreement among experts and a lack of robust evidence.
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In 2025, after new studies and global collaboration, the International Diabetes Federation officially reinstated and named it Type 5 diabetes at the World Diabetes Congress. This recognition was driven by evidence showing that decades-long patterns of childhood undernutrition can permanently change how the pancreas regulates blood sugar.
This long journey reflects how science evolves and how diseases that were once overlooked can gain recognition when research uncovers their distinct features and impacts.
4. Why Official Recognition Matters
The formal recognition of Type 5 diabetes is far more than a semantic change — it has real implications for healthcare systems, patients, and global health priorities.
Better Diagnosis
Before recognition, many people with this condition were misdiagnosed as having type 1 or type 2 diabetes. Because their underlying metabolic profiles differ substantially, this misclassification often led to suboptimal treatment plans.
Improved Treatment
Recognizing Type 5 as a unique form of diabetes allows clinicians to tailor treatment strategies that better match its causes and risks, reducing the chances of complications from inappropriate therapies like overly aggressive insulin dosing.
Public Health Awareness
Millions of people worldwide — particularly in regions with high poverty and undernutrition — may be living with Type 5 diabetes without understanding the root cause of their illness. Official recognition helps shift public health focus toward prevention of malnutrition alongside blood sugar control.
Resource Allocation
Healthcare planners and global health organizations can now allocate research funding and clinical resources toward understanding and managing Type 5 diabetes specifically, rather than lumping these patients into broader diabetes categories where their needs might be ignored.
5. Who Is at Risk for Type 5 Diabetes?
Type 5 diabetes affects a distinct demographic compared to type 1 and type 2:
Typical Risk Profile
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Lean individuals (often with body mass index [BMI] lower than average).
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Young people, particularly adolescents or adults under age 30.
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Individuals from low- and middle-income countries or communities where chronic undernutrition is common, including parts of Asia, Africa, Latin America, and the Caribbean.
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Those with a history of childhood malnutrition or inadequate nutrition during developmental years.
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Some people in higher-income countries with histories of starvation, prolonged food insecurity, or very limited nutrient intake may also be at risk.
Unlike type 2 diabetes, being overweight is not a risk factor for Type 5. Instead, the defining risk factor is nutritional deficiency during key developmental periods, especially protein and micronutrients needed for pancreatic growth and function.
6. Symptoms of Type 5 Diabetes
The symptoms of Type 5 diabetes can resemble those of other forms of diabetes, since they all stem from problems regulating blood sugar. Common signs include:
Typical Symptoms
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Frequent urination (polyuria)
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Excessive thirst (polydipsia)
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Unexplained weight loss, even without decreased appetite
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Extreme fatigue or weakness
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Poor wound healing
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Increased susceptibility to infections
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Elevated blood sugar levels detected on testing
Notably, unlike type 1 diabetes, Type 5 diabetes does not typically cause ketosis or ketone production, where the body breaks down fat for energy because it lacks insulin. This is an important clinical distinction. Patients may have high blood sugar but remain ketone-negative.
7. How Type 5 Diabetes Works: Pathophysiology
At the heart of Type 5 diabetes is the failure of the pancreas to develop normal insulin-producing capacity due to chronic undernutrition.
In healthy individuals, the pancreas’ beta cells produce insulin — a hormone that helps glucose enter cells and be used for energy. In Type 5 diabetes:
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Chronic lack of essential nutrients during childhood and adolescence leads to underdeveloped pancreatic function.
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The pancreas may produce some insulin, but not enough to regulate blood sugar effectively.
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Unlike type 1, the body’s immune system does not attack the beta cells.
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Unlike type 2, there is no predominant insulin resistance in tissues.
This unique metabolic fingerprint means that a person with Type 5 diabetes is insulin deficient but often still sensitive to whatever insulin their body can produce — a combination that requires careful therapeutic balance to avoid dangerously low blood sugar if treated like other insulin-deficient types.
8. Diagnosing Type 5 Diabetes
Because many healthcare providers have traditionally used frameworks focused on types 1 and 2, diagnosing Type 5 diabetes can be challenging. However, clinicians look for a distinct set of clues:
Key Diagnostic Considerations
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History of long-term malnutrition or food insecurity, especially during childhood.
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Low or normal BMI despite high blood sugar levels.
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Absence of autoimmune markers that would suggest type 1 diabetes.
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Low insulin secretion patterns — measured through C-peptide levels, which reflect the body’s own insulin production.
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Normal or preserved insulin sensitivity — unlike type 2 diabetes, where tissues become resistant.
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No ketones or only minimal ketosis, even with high glucose readings.
Diagnosis typically involves comprehensive blood tests, assessing insulin and glucose levels, and careful history taking. Because official diagnostic criteria are still being developed (with working groups established by the IDF), clinicians must use clinical judgment and emerging guidelines.
9. Treatment and Management of Type 5 Diabetes
Treating Type 5 diabetes requires a different strategy than conventional diabetes protocols:
Nutrition First
Since chronic undernutrition lies at the root, nutritional rehabilitation is a cornerstone of care. This typically includes:
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Increasing protein intake.
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Ensuring adequate calories for growth and metabolic needs.
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Addressing micronutrient deficiencies.
Careful Insulin Use
While insulin might be necessary for some people, it must be prescribed cautiously:
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People with Type 5 are often more insulin sensitive.
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Standard insulin doses designed for type 1 diabetes can trigger dangerously low blood sugar (hypoglycemia) if not carefully monitored.
Oral Medications
In some cases, people with Type 5 diabetes may benefit from oral glucose-lowering medications instead of or in addition to low doses of insulin. These need to be prescribed with careful consideration of nutritional status and metabolic needs.
Lifestyle and Monitoring
Regular blood sugar monitoring, a balanced diet, and close medical supervision are essential. Because formal treatment guidelines are still emerging, clinicians often tailor care based on individual metabolic profiles.
10. Differences Between Type 5 and Other Types of Diabetes
Understanding how Type 5 diabetes differs from classic diabetes types helps highlight why its recognition matters:
| Feature | Type 1 | Type 2 | Type 5 |
|---|---|---|---|
| Cause | Autoimmune destruction of beta cells | Insulin resistance & relative deficiency | Chronic undernutrition affecting pancreatic development |
| Typical BMI | Any (often lean) | Often overweight | Often underweight |
| Insulin Levels | Very low | Normal or high with resistance | Low but sometimes responsive |
| Autoimmune markers | Often present | Absent | Absent |
| Ketosis | Common if untreated | Rare | Generally absent |
11. Real-World Impact: How Many People Are Affected?
While research continues, current estimates suggest that millions of people worldwide may have Type 5 diabetes — particularly in Asia and Africa where chronic undernutrition has historically been widespread.
Studies suggest that roughly 20 to 25 million individuals may live with this condition, a number comparable to major global health burdens. Given that many cases have historically been misclassified, these figures could rise further as awareness and screening improve.
12. Why Some Experts Urge Caution
It’s important to note that not all researchers agree on every detail of Type 5 diabetes. Some argue that more study is needed to fully map its pathophysiology. Others emphasize that evidence is still emerging about the best diagnostic tools and treatments. However, the fact that the International Diabetes Federation has given this form of diabetes an official classification reflects a broad consensus that it is a meaningful and distinct clinical entity.
13. Preventing Type 5 Diabetes
Because Type 5 diabetes is closely linked to lifelong nutritional status, prevention strategies focus on supporting adequate nutrition from early life:
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Ensuring pregnant women receive sufficient macro- and micronutrients.
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Providing children with access to balanced diets rich in protein and essential vitamins.
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Combating poverty and food insecurity through public health and social support programs.
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Targeted nutritional programs in high-risk communities.
By ensuring adequate early-life nutrition, it may be possible to reduce the long-term risk of developing this condition.
14. Should You Be Worried? Recognizing the Signs
If you or someone you know experiences high blood sugar readings along with:
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A low or normal body weight,
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A history of childhood malnutrition,
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No family history of traditional diabetes, and
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Typical diabetes symptoms like frequent urination, thirst, or weight loss,
…then it might be worth discussing with a healthcare provider whether Type 5 diabetes could be a consideration.
Only proper medical testing can make an accurate diagnosis, and early identification can help ensure appropriate care and avoid complications from incorrect treatments.
15. Looking Ahead: Research and Challenges
Now that Type 5 diabetes is officially recognized, global research priorities are shifting:
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Scientists are developing standard diagnostic criteria.
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Clinical trials aim to determine best treatment strategies.
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Public health agencies are exploring screening programs for at-risk populations.
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Longitudinal studies will clarify long-term outcomes and prevention strategies.
Recognition is a major step, but many questions remain — including the best way to integrate Type 5 diabetes into healthcare systems around the world.
Conclusion
The official recognition of Type 5 diabetes marks a new chapter in how the medical community understands blood-sugar disorders. It highlights an important truth: diabetes is not a single disease with a single cause, but a spectrum of conditions driven by different metabolic pathways. In the case of Type 5, long-term undernutrition has lifelong consequences, reshaping pancreatic function and leading to a unique form of diabetes that demands tailored care.
As awareness grows and diagnostic tools improve, people with this condition can benefit from better-targeted treatments and support. Understanding the signs — especially in individuals who are lean and have histories of nutritional deficits — is key to early diagnosis and appropriate care. Most importantly, Type 5 diabetes reminds us that public health is deeply linked with nutrition and social equity: tackling poverty and food insecurity may not only reduce hunger — it can also prevent chronic disease.
