In 2025, the International Diabetes Federation (IDF) officially recognized a

fifth form of diabetes, called "type 5 diabetes," directly linked to malnutrition or undernutrition. This new type, long referred to as "malnutrition diabetes," was presented on April 8, 2025, at the World Diabetes Congress in Bangkok, Thailand.

According to the journal "The Lancet Global Health," this form of diabetes primarily affects low-income countries, where chronic malnutrition remains a major public health problem. It estimates that nearly 25 million people worldwide are affected by this type 5.

This type of diabetes primarily affects young people under the age of 30. Unlike type 1, insulin production is reduced, but rarely absent. And unlike type 2, patients with the condition are not overweight: on the contrary, they are thin or underweight, a direct consequence of an insufficient or unbalanced diet.

The recognition of type 5 represents a major step forward in better diagnosing and treating this form of the disease, which has long been neglected in official diabetes classifications.

Until this recent recognition, four main types of diabetes were distinguished:

Type 1, an autoimmune disease that often appears in children; type 2, linked to lifestyle and more common in adulthood; gestational diabetes, occurring during pregnancy; MODY (Maturity Onset Diabetes of the Young), a hereditary and often silent form.

Type 5 now completes this classification, highlighting the decisive impact of nutrition in the onset of diabetes, and shedding light on a long-ignored reality affecting the most vulnerable populations.