Type 5 Diabetes
When Malnutrition Shapes Diabetes Risk
Most conversations about diabetes revolve around type 1 and type 2. But not all diabetes fits neatly into those categories.
In 2025, the International Diabetes Federation formally recognised Type 5 diabetes — a form of diabetes driven by chronic undernutrition, rather than autoimmunity or insulin resistance. Long described in parts of the world affected by food insecurity, this form of diabetes has often been misdiagnosed or overlooked. Its recognition challenges some of the most common assumptions about what causes diabetes and who is affected by it.¹
What is Type 5 diabetes?
Type 5 diabetes, historically referred to as malnutrition-related diabetes mellitus (MRDM) or J-type diabetes, is characterised by insulin deficiency arising from impaired pancreatic development due to prolonged undernutrition, particularly during early childhood and adolescence. Unlike type 1 diabetes, which results from autoimmune destruction of pancreatic beta cells, Type 5 diabetes reflects structural and functional pancreatic compromise caused by nutritional deprivation. It also differs fundamentally from type 2 diabetes, which is predominantly driven by insulin resistance.¹
In early 2025, an international expert group reviewed decades of clinical observations and emerging metabolic research. Their conclusions were formally endorsed at the IDF World Diabetes Congress 2025, leading to the recognition of Type 5 diabetes as a distinct diagnostic category.¹,²
Why recognition matters
For decades, individuals with this form of diabetes were frequently misclassified as having either type 1 or type 2 diabetes. This often resulted in inappropriate treatment strategies, delayed diagnosis, and increased risk of complications.
Formal recognition by the IDF aims to:
- improve diagnostic accuracy;
- stimulate targeted research into pathophysiology and treatment;
- raise clinician awareness globally; and
- address long-standing inequities in diabetes care rooted in poverty and food insecurity.¹
To support this work, the IDF has established a Type 5 Diabetes Working Group tasked with developing diagnostic criteria, treatment guidance, and international research collaboration.²
Clinical features and presentation
Type 5 diabetes most commonly presents in lean adolescents or young adults with a history of chronic undernutrition. Typical features include:
- persistent hyperglycaemia with classical symptoms such as polyuria and polydipsia;
- low body mass index (BMI);
- severe insulin deficiency without autoimmune markers;
- relative resistance to ketosis despite marked hyperglycaemia.¹,³
Metabolic studies suggest that the central defect is reduced insulin secretion rather than insulin resistance, which has important implications for treatment choice and dosing.³
Epidemiology and populations affected
Although precise prevalence data are still emerging, the IDF estimates that 20–25 million people worldwide may be living with Type 5 diabetes, predominantly in South Asia, sub-Saharan Africa, and other low- and middle-income regions.²,⁴
Risk is closely linked to early-life nutritional deprivation, recurrent infections, poor maternal nutrition, and long-term food insecurity. Importantly, Type 5 diabetes may also be encountered in migrant or refugee populations who experienced undernutrition earlier in life but now reside in high-income countries.¹
Historical context: recognised, removed, rediscovered
The association between diabetes and severe malnutrition was first described in the 1950s, with cases reported in the Caribbean and South Asia. The World Health Organization formally recognised MRDM as a distinct category in the 1980s, but removed it from classification in 1999, citing limited evidence and diagnostic ambiguity.⁵
As a result, this form of diabetes largely disappeared from clinical teaching and research agendas. The renewed recognition in 2025 reflects both advances in metabolic science and sustained advocacy from clinicians working in regions where this condition has never truly disappeared.¹,²
Ongoing debates and challenges
Despite its formal recognition, debate remains regarding diagnostic thresholds, biomarkers, and heterogeneity within Type 5 diabetes. Some researchers caution that clearer phenotyping and longitudinal data are needed. However, many view classification as a necessary foundation for improving recognition, research investment, and patient care, rather than an endpoint.²
Treatment considerations
Given its underlying biology, Type 5 diabetes requires a different therapeutic lens from type 2 diabetes. Key considerations include:
- insulin therapy may be required but at lower doses than typically used in type 1 diabetes;
- common oral glucose-lowering agents may be ineffective;
- nutritional rehabilitation is central to management and long-term outcomes.¹,³
Evidence-based treatment guidelines are currently under development by the IDF working group.²
Why Type 5 diabetes matters
Type 5 diabetes underscores a critical reality: diabetes is shaped not only by genetics and lifestyle, but also by social and environmental forces. Recognising this form of diabetes broadens understanding of the disease and challenges oversimplified narratives that focus solely on obesity or individual behaviour.
In acknowledging Type 5 diabetes, the global diabetes community takes an important step toward a more inclusive, biologically accurate, and compassionate understanding of diabetes.¹
Type 5 diabetes sits within a broader, evolving understanding of diabetes classification. If you’d like to explore how and why diabetes is classified — and why the traditional ‘type 1 vs type 2’ model is often too simple — see the Deep Dive Classification of Diabetes
Type 5 diabetes in the context of Aotearoa New Zealand
It is important to be clear about relevance. Type 5 diabetes is not currently recognised as a common or defining contributor to diabetes among people living in Aotearoa New Zealand, including Māori and Pacific peoples.
Type 5 diabetes develops in the setting of severe, prolonged undernutrition, particularly during early childhood, leading to impaired pancreatic development and lifelong insulin deficiency. This pattern is more commonly seen in regions affected by famine, extreme food insecurity, or humanitarian crisis. It does not reflect the predominant biological pathways driving diabetes risk for Māori or Pacific peoples in Aotearoa, where diabetes arises from a far more complex interplay of colonisation, social and economic inequity, environmental change, metabolic risk, and access to timely care.
At present, there is no evidence that Type 5 diabetes explains the higher prevalence of diabetes seen among Māori or Pacific peoples in New Zealand, and it should not be used as an explanatory label for those inequities.
Why this discussion still matters in Aotearoa
Although Type 5 diabetes itself is unlikely to be common in New Zealand, the principles it highlights remain relevant.
1. Early-life nutrition matters — everywhere
Not because Māori or Pacific peoples are undernourished in the same way, but because:
- fetal and childhood nutrition
- infection burden
- stress and deprivation
all shape metabolic health across the life course
This aligns with developmental origins of health and disease (DOHaD) thinking, which is highly relevant in NZ.
2. Misclassification harms people
Type 5 diabetes reminds us that:
- diabetes does not look the same in every body
- assumptions based on weight, ethnicity, or age can lead to inappropriate treatment
That lesson absolutely applies in Aotearoa, where Māori and Pacific peoples are often:
- diagnosed later
- treated more aggressively or less flexibly
- framed through stereotypes rather than physiology
3. Social context shapes biology
Not equivalence — but resonance. Type 5 diabetes reinforces that:
diabetes risk is shaped by lived experience, not personal failure
A te ao Māori perspective
Within te ao Māori, health is understood as inseparable from whakapapa, whenua, whānau, and wairua. The concept that early-life conditions can shape health across generations aligns closely with Māori understandings that wellbeing is carried forward through whakapapa — influenced not only by biology, but by lived experience, deprivation, stress, and disruption of connection to land and community.
Type 5 diabetes serves as a reminder — not a parallel — that bodies carry history. It reinforces the importance of looking beyond individual behaviour to the wider systems and conditions that shape hauora across the life course. This perspective supports strengths-based, holistic approaches to diabetes care for Māori, without importing a diagnostic label that does not fit the New Zealand context.
A Pacific perspective
Pacific models of health similarly emphasise collective wellbeing, balance, and relational identity, where physical health is deeply connected to family, culture, spirituality, and environment. While the severe undernutrition associated with Type 5 diabetes is not characteristic of most Pacific communities in Aotearoa, the condition highlights how early-life adversity and structural inequity can shape metabolic health decades later.
For Pacific peoples, this reinforces the need for diabetes approaches that recognise intergenerational experience, migration histories, food environments, and socioeconomic pressures — rather than framing diabetes risk through narrow or individualised explanations.
A shared lesson
Type 5 diabetes reminds us that diabetes is not a single disease, nor a simple outcome of personal choice. It is shaped by biology, environment, history, and lived experience. In Aotearoa New Zealand, this understanding strengthens — rather than replaces — Māori and Pacific approaches to diabetes that centre whānau, community, dignity, and context.
A note on relevance:
Type 5 diabetes remains rare in high-income countries such as Aotearoa New Zealand. Its discussion here is intended to broaden understanding of diabetes classification globally, not to explain diabetes patterns among Māori or Pacific peoples in New Zealand.
Understanding Type 5 diabetes is a reminder that diabetes is not a single disease, but a spectrum shaped by biology, environment, and lived experience.
References
-
International Diabetes Federation. Type 5 diabetes. Brussels: IDF; 2025.
Available from: https://idf.org/about-diabetes/types-of-diabetes/type-5-diabetes/ -
International Diabetes Federation. IDF launches Type 5 diabetes working group. Brussels: IDF; 2025.
Available from: https://idf.org/news/new-type-5-diabetes-working-group/ -
Tucker ME. Malnutrition-related diabetes officially named type 5. Medscape. 2025.
Available from: https://www.medscape.com/viewarticle/malnutrition-related-diabetes-officially-named-type-5-2025a10008pd -
NDTV. Type 5 diabetes officially recognised: what we know so far. NDTV Science. 2025.
Available from: https://www.ndtv.com/science/type-5-diabetes-officially-recognised-all-about-this-malnutrition-linked-disease-affecting-millions-8422711 -
Ust Hadian T. Type 5 diabetes recognised as distinct condition by International Diabetes Federation. 2025.
Available from: https://www.usthadian.com/type-5-diabetes-recognized-as-distinct-condition-by-international-diabetes-federation/
Linked Article: Understanding Diabetes beyond the Labels
Published: December 2025
