Study reveals weight loss may not prevent type 2 diabetes

Weight loss is considered an important factor in maintaining overall health and reducing the risk of several diseases. 

However, a new study suggests that losing weight alone may not be enough to prevent type 2 diabetes in some high-risk individuals.

Even after losing about 8% of their body weight and keeping it off for years, people in a high-risk category known as cluster 5 continued to experience rising blood sugar, weakening insulin production, and a strong risk of developing diabetes.

The researchers analyzed information from the Tubingen Lifestyle Intervention Program (TULIP). People with an increased risk of type 2 diabetes participated in a two-year lifestyle program and were then monitored for approximately nine years.

The analysis concentrated on participants who achieved substantial weight loss and successfully maintained it over the long term.

Professor Norbert Stefan, the lead author of the study said, "We were very surprised to find that, despite a large and sustained weight loss of 8% and after a very long follow-up period of 9 years, individuals showed increasing blood glucose levels, declining insulin secretion, and a persistently high risk of type 2 diabetes."

The analysis was focused on the biological mechanisms that might explain the group's worsening metabolic health.

The findings published in the journal Diabetes, 2026 support earlier evidence showing that fatty liver disease and insulin resistance are the main disease processes affecting people in Tubingen's type 2 diabetes risk.

Rsearchers suggest if future prospective research confirms the findings, diabetes prevention may need to become more personalized and people with high-risk biological profiles may require more intensive care or treatments designed to address their specific metabolic problems.

Notably, the materials provided for the TULIP study, "Different Metabolic Responses to Long-term Weight Loss After Lifestyle Intervention Among Type 2 Diabetes Risk Clusters" were collected from Deutsches Zentrum fuer Diabetesforschung DZD.