Dozens of experts have urged health officials to formally recognise a neglected form of diabetes that affects young, slim people.

The seldom-discussed type 5 diabetes is thought to affect up to 25 million people worldwide and is triggered by insufficient food intake.

Diabetes occurs when the body either can’t produce enough insulin—a hormone that controls the level of sugar in the blood—or use it effectively.

New findings indicate this emerging condition typically affects teenagers and young adults who are underweight or have faced severe food shortages during childhood, as malnutrition hampers their insulin secretion ability.

Experts researching the condition say it has mainly been seen in slim teenagers and young adults in low and middle-income countries. 

But it is feared type 5 diabetes may be misdiagnosed or not treated properly due to ‘lack of evidence-based treatment guidelines’, scientists said. 

In an article for the esteemed journal Lancet Global Health, 50 researchers from 11 countries, including the UK, stated: ‘We call upon the international diabetes community to recognise this distinct form of the disease.

‘It likely affects the quality and length of life of millions of people worldwide. 

Known as ‘Type 5 diabetes’ or Maturity Onset Diabetes of the Young (Mody), it is believed to affect up to 25 million people globally

‘We urge global entities such as the International Diabetes Federation and World Health Organization (WHO) to advocate for more research into the attributes, mechanisms, and treatments of type 5 diabetes.’

The term first appeared in medical reports in Jamaica in 1955. 

Three decades later, the WHO officially classified ‘malnutrition-related diabetes mellitus’ as a distinct diabetes type.

But the UN agency then dropped the category in 1999 due to a lack of evidence.

Type 1 diabetes, unrelated to lifestyle, results when the pancreas cannot produce insulin, causing the patient’s blood sugar levels to rise dangerously.

Type 2 diabetes, meanwhile, occurs when the body doesn’t make enough insulin or the insulin it makes doesn’t work properly. 

This hormone is needed to bring down blood sugar levels. It is the most common form of diabetes, making up 95 per cent of global cases.

Two other rare forms of diabetes—3 and 4—are recognised and caused by pancreatic diseases like cystic fibrosis and pregnancy respectively.

Nearly 4.3 million people were coping with diabetes in 2021/22 per the latest UK data, and an additional 850,000 individuals are unaware they have diabetes, which is concerning since untreated type 2 diabetes can lead to heart disease and strokes.

But type 5, say doctors, is a distinct condition in its own right. 

People with this form can produce insulin and are not resistant to it, but their pancreas is underdeveloped and cannot make enough.

Because of this, treating type 5 like type 1 or type 2 is often ineffective—even harmful.

Reports also suggest the condition mainly affects young men in Asia and Africa.   

It’s thought that undernutrition in the womb, followed ‘persistent undernutrition during childhood and adolescence’ can increase the risk, according to researchers.

While evidence suggests that at least 25 million people may be affected by type 5 diabetes, the report authors said it remains under-recognised and under-researched.

‘Misdiagnosis and underdiagnosis are likely to have negatively impacted the clinical care and lives of millions of individuals worldwide,’ the report noted.  

Dr Allan Vaag, a professor of endocrinology at Lund University in Sweden and one of the Lancet paper’s co-authors, also told The Telegraph: ‘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 have suggested that to manage type 5 diabetes, patients should include much higher amounts of protein and complex carbohydrates, such as lentils, legumes and grains, in their diet. 

Evidence has long shown that diets higher in fibre and proteins can help patients with diabetes to slow down the digestion of carbs and delay their absorption into the blood. 

This helps to prevent spikes in blood sugar levels after eating.

The chronic condition diabetes now affects 4.6 million people in the UK—a record high, according to the charity Diabetes UK.

It can be a deadly illness and it costs the NHS roughly £10 billion a year to treat, with patients at higher risk of damage to organs, nerves and cells.

It also dramatically increases the risk of heart disease, kidney disease, amputations and sight loss.