Article by Dr Manasa S, B.A.M.S

Introduction

Type 5 diabetes is a distinct, underrecognized subtype of diabetes mellitus that primarily affects undernourished adolescents and young adults (BMI <18.5 kg/m²).

It differs etiologically and clinically from Type 1 and Type 2 diabetes. Whereas Type 1 is autoimmune and Type 2 is driven by insulin resistance, Type 5 arises from chronic malnutrition leading to irreversible pancreatic damage and significantly reduced insulin secretion.

Emerging evidence indicates insulin production may be up to 70% lower in affected individuals compared to healthy controls, despite the absence of insulin resistance.

Predominantly found in regions with high rates of early-life undernutrition, Type 5 diabetes was officially recognized by the International Diabetes Federation (IDF) in 2025, prompting the development of targeted diagnostic and treatment strategies.

A Long-Awaited Step toward Recognition and Reform

The IDF’s formal recognition of Type 5 diabetes in 2025 marked a pivotal shift in global diabetes care. Previously misclassified under other diabetes types, this reclassification validated clinical observations from decades past. It also highlighted the severe impact of food insecurity—from maternal malnutrition through chronic childhood undernourishment—on pancreatic health.

Type 5 is now acknowledged as a distinct, insulin-deficient condition caused by malnutrition-induced pancreatic dysfunction.

 

Malnutrition

↓

Pancreatic dysfunction

↓

Insulin deficiency

↓

Type 5 Diabetes

This has enabled the development of relevant clinical frameworks tailored to resource-limited settings.

 Historical Background of Type 5 Diabetes

–         1955: Identified in Jamaica as “J-type diabetes.”

–         1985: WHO introduced the term “malnutrition-related diabetes mellitus (MRDM)”

–         1999: WHO withdrew the MRDM classification due to insufficient data

–         Post-1999: Consistent case patterns reported across Sri Lanka, Bangladesh, Uganda, Ethiopia, and Rwanda.

–         2023: A Lancet meta-analysis linked early malnutrition with pancreatic dysfunction.

–         Early 2025: IDF reclassified the condition as Type 5 diabetes.

–         April 2025: Official endorsement marked its entry into the global diabetes taxonomy.

Epidemiology

Geographic Distribution:

–         Prevalent in South Asia, Sub-Saharan Africa, Central America, and the Caribbean.

–         Common in rural, low-income populations with endemic undernutrition.

Estimated Prevalence:

–         3–5 million cases worldwide may be misdiagnosed or undiagnosed.

–         In some paediatric clinics, Type 5 accounts for 10–20% of atypical diabetes cases.

Demographics:

–         Slight male predominance noted.

–         Onset typically in late adolescence to early adulthood following prolonged undernutrition.

Risk Factors

–         Early-life protein-energy malnutrition.

–         Recurrent gastrointestinal infections.

–         Maternal malnutrition.

–         Food insecurity and poverty.

Patho-physiology

Malnutrition-Driven Beta Cell Failure

Type 5 diabetes is driven by non-autoimmune, non-genetic beta cell destruction due to prolonged undernutrition. Insulin secretion may be reduced by up to 70%.

Mechanisms include:

–         Protein-energy malnutrition impairs pancreatic development.

–         Micronutrient deficiencies (zinc, vitamin A, essential amino acids) affecting insulin synthesis.

–         Chronic infections leading to pancreatic inflammation and fibrosis.

The resulting low-insulin phenotype is often misclassified as Type 1, leading to inappropriate insulin therapy.

Key Clinical Features

Clinical Feature	Description
Persistent Fatigue	Chronic, unexplained fatigue resistant to rest
Unintentional Weight Loss	Despite normal or increased caloric intake
Recurrent Infections	Skin, urinary, or respiratory infections resistant to treatment.
Low Body Fat Percentage	10–12% vs. 20–25% in healthy adults.
Nutritional Deficiencies	Protein, zinc, vitamin A deficiencies commonly present.
No Autoimmune Markers	Negative for GAD65, IA-2, ZnT8 antibodies.

Diagnostic Criteria

Diagnosis is clinical and based on exclusion, especially in low-resource settings.

Proposed Criteria:

Age of Onset: 10–30 years (typically adolescence or early adulthood).

BMI: <18.5 kg/m² or history of undernutrition.

Insulin Secretion Profile:

–         Low fasting C-peptide

–         Low fasting insulin

–         Absence of insulin resistance

Autoimmunity: Negative autoantibodies (GAD65, IA-2, ZnT8).

Nutritional History: Chronic malnutrition, micronutrient deficiencies.

Pancreatic Imaging (if available): Atrophy or reduced pancreatic volume.

Exclusion of Other Types: No family history of Type 2, no obesity, no DKA at onset.

Treatment Approaches and Future Directions

Nutritional Therapy: Cornerstone of Care

–         High-protein diets (legumes, eggs, dairy, fish) to restore lean mass and β-cell function.

–         Balanced intake of carbohydrates and healthy fats tailored to BMI and activity.

–         Micronutrient supplementation (zinc, vitamin A, vitamin D, B-vitamins).

Pharmacologic Support

–         Metformin: Used cautiously in stable patients with mild hyperglycemia and preserved renal function.

–         Low-Dose Insulin: Considered when insulin levels are critically low; requires careful monitoring.

–         Avoid High-Dose Insulin: Risk of hypoglycaemia in malnourished patients with low caloric intake.

Standardized Protocols

–         IDF-led development of clinical guidelines.

–         Training programs for healthcare providers in LMICs.

–         Integration with nutrition and maternal-child health services.

Future Directions

–         Longitudinal studies to track outcomes and disease progression.

–         Development of point-of-care diagnostics for LMICs.

–         Policy advocacy for integrating nutrition with NCD care.

Related Research and Studies

Malnutrition Related Diabetes Officially Named ‘TYPE 5’

International Diabetes Federation (IDF) Designates ‘Type 5 Diabetes’ to address Malnutrition-Related Form of Disease

Diabetes consists of Five Types, Not Two, Say Researchers

Type-5 Diabetes: Ayurveda Understanding

The patients of Prameha – a condition often studied alongside Diabetes (in close correlation) are broadly classified as Sthula Pramehi – obese patients of prameha and Krsha Pramehi – lean or emaciated patients of Prameha.

Leanness or emaciation can occur due to undernourishment or chronic malnutrition. Therefore patients of Type-5 Diabetes shall be considered under the discussion of Krsha Pramehi.

There is no detailed description of Krsha Pramehi in Ayurveda treatises. On the other hand it is said that this condition shall be treated with the help of Brmhana therapy – stoutening, strengthening or bulk promoting medicines, foods and treatments. In this context it should be understood as a treatable condition, like Type-5 Diabetes.

It also appears that this condition is a ‘vata predominant condition’. This is because undernourishment or chronic malnutrition causes tissue loss and tissue loss leads to vata aggravation. This aggravated vata once again causes further tissue damage. This condition runs in vicious cycle. But Type-5 Diabetes cannot be correlated with Vataja Prameha caused due to severe tissue damage because of the later condition having bad prognosis and has been declared as incurable.

Vataja Prameha caused due to its association with aggravated pitta or kapha or being blocked (avarana) by pitta or kapha with mild to moderate tissue destruction and having favourable prognosis can be considered as Type-5 Diabetes. These conditions can be treated with anti-vata treatments and medicines along with Brmhana Chikitsa.

Related Reading – ‘Type-5 Diabetes – Ayurveda Understanding’.