Twenty-five million cases just got a number: type 5
The International Diabetes Federation named malnutrition-related diabetes type 5 in 2025, ending a 70-year dispute.
By The Weekend · · 5 min read
In 2025, the International Diabetes Federation gave a name to a disease that had existed, unnamed and mistreated, for 70 years. Type 5 diabetes — caused not by autoimmunity or lifestyle but by chronic nutrient deficiency — is now estimated to affect up to 25 million people, most of them in low- and middle-income countries where the condition was first dismissed, then forgotten, then fought over.
A patient in rural India gets a different diagnosis, and a different drug
The practical stakes sit in a single clinical decision. Someone underweight, insulin-deficient but not insulin-resistant, walks into a clinic showing high blood sugar. Under the old binary, the working assumption defaults to type 2 — the insulin-resistance diagnosis that drives most of the world's diabetes prescribing — and the treatment follows: drugs designed to make the body respond better to insulin it already makes too much of. Type 5 patients don't have that problem. Their pancreas develops poorly after years of malnutrition and produces too little insulin outright. Giving a type 2 drug to someone whose issue is production, not resistance, doesn't just fail to help. Researchers studying the condition say it can actively harm.
Meredith Hawkins, an endocrinologist at the Albert Einstein College of Medicine, ran the small trial in south India in 2022 that gave this distinction its first hard data: people with malnutrition-related diabetes were insulin-deficient like type 1 patients, but to a lesser degree, and remained sensitive to insulin — the opposite metabolic signature from type 2. That's the difference between a drug that helps and one that doesn't.
The number is old. The paperwork is new.
The condition was first described in Jamaica in 1955, under the heading of malnutrition-related diabetes mellitus. The World Health Organization acknowledged it in the 1980s, then withdrew the classification in 1999, citing insufficient evidence — a reversal that effectively erased it from clinical guidelines and, more consequentially, from research funding. A disease without a standardized name is a disease no grant committee can easily fund and no drug trial can easily recruit for. That gap ran for a quarter of a century.
What changed wasn't a single breakthrough but an accumulation: animal studies and human cohorts through the 2010s and 2020s showing that sustained nutrient deprivation — not just in utero or in infancy, but across years — leaves lasting damage to the pancreas's insulin-secreting capacity. Hawkins' 2022 metabolic profiling gave the condition its first quantifiable signature distinct from type 1 and type 2. The IDF's 2025 recognition formalizes that body of work into an official classification and, notably, urges the WHO to follow — the body whose 1999 withdrawal is precisely what needs reversing for the diagnosis to carry weight in national health systems and insurance coding worldwide.
Recognition doesn't settle who counts
The catch is that naming a disease doesn't resolve how to diagnose it, and that argument is still live. Craig Beall, a diabetes researcher at the University of Exeter, has called getting treatment right contingent on getting the type right — but the physicians skeptical of the 2025 move aren't disputing the biology so much as the boundary. Some researchers call the recognition "long overdue." Others call it "unwarranted," citing "diagnostic uncertainty": malnutrition-related diabetes shows up with varying presentations, and without an agreed diagnostic test, some fraction of the 25 million estimated cases could be misclassified — people who actually have type 1 or an unusual type 2 presentation, swept into a new category because clinicians now have somewhere to put ambiguous cases. That's not a trivial objection. It's the same evidentiary gap that got the diagnosis withdrawn in 1999, and formal naming doesn't automatically close it. What closes it is standardized diagnostic criteria, which don't yet exist, and funded trials, which can now at least be proposed under an official heading.
There's also a flat disagreement on direction: some researchers report rising case numbers, others say prevalence is falling, and the IDF's own position is that this disagreement is itself a symptom of under-diagnosis rather than a resolved fact. Hawkins has pointed out that malnutrition-related diabetes is more common globally than tuberculosis and nearly as common as HIV — diseases with dedicated global health infrastructure, surveillance systems and funding lines that type 5 diabetes has never had.
Twenty-five million people, mapped onto places with the least diagnostic capacity
The populations most affected — in parts of Asia and Africa experiencing severe food insecurity — are also the places least equipped to run the kind of metabolic testing Hawkins' team used to distinguish type 5 from type 1 and type 2. A classification is only useful where someone can test for it. For now, the condition is likely to remain under-captured in exactly the regions where it's most common, which means the 25 million estimate is almost certainly a floor, not a ceiling.
The honest open question is whether naming the disease actually redirects money toward it, or whether type 5 diabetes spends the next decade the way it spent the last seven — officially real, clinically under-resourced. Formal recognition unlocks the possibility of dedicated trials and funding applications. It does not, by itself, produce a diagnostic test, a treatment protocol, or a line item in any health ministry's budget. Those require separate fights, and the IDF's move only buys a ticket to have them.
Is type 5 diabetes treatable?
There's no established standard treatment yet; existing type 1 and type 2 drugs may not work and some may cause harm, so management currently leans on nutritional rehabilitation and careful insulin dosing under specialist care.
Can type 5 diabetes be reversed?
Some pancreatic damage from prolonged malnutrition appears to be structural, so prevention through nutrition is currently the more realistic lever than reversal once the condition is established.