The Game-Changing Research That's Rewriting Diabetes Prevention
When most people hear "Mediterranean diet," they think of olive oil, fresh vegetables, and maybe a glass of red wine. But Spanish researchers just proved there's an even smarter way to eat Mediterranean-style—and the results are nothing short of remarkable.
The PREDIMED-Plus study, Europe's largest nutrition trial led by the University of Navarra, found that a calorie-reduced Mediterranean diet combined with moderate exercise and professional support cuts type 2 diabetes risk by 31%. That means roughly three out of every 100 people following this approach won't develop diabetes—a massive win for public health.
What Makes This Study Different?
Launched in 2013 after receiving over €2 million from the European Research Council, PREDIMED-Plus brought together more than 200 researchers from 22 universities, hospitals, and research institutes across Spain. The study followed 4,746 adults between ages 55 and 75 who were overweight or obese with metabolic syndrome but no prior diabetes or cardiovascular disease.
Unlike the original PREDIMED study that simply looked at Mediterranean eating, this new trial added three crucial elements:
1. Calorie Control: Participants reduced their daily intake by roughly 600 calories
2. Physical Activity: Moderate exercise like brisk walking or light strength training was incorporated
3. Professional Support: Regular guidance and counseling for weight management
The results speak for themselves.
The Numbers Don't Lie
After six years, the differences between the intervention group and the control group (who followed a standard Mediterranean diet without restrictions) were striking:
The intervention group lost an average of 3.3 kilograms (7.3 pounds) and trimmed 3.6 centimeters (1.4 inches) from their waistlines, compared to just 0.6 kilograms and 0.3 centimeters in the control group.
But the weight loss wasn't the headline—the dramatic reduction in diabetes risk was.
During the 6-year follow-up, type 2 diabetes incidence was 31% lower in the intervention group compared to control, with 280 cases in the intervention group versus 349 cases in the control group.
Why This Matters Now
Type 2 diabetes now affects more than 530 million people worldwide, and the numbers keep climbing. In Spain alone, 4.7 million adults live with diabetes, while Europe has more than 65 million cases and the United States has approximately 38.5 million.
The disease doesn't just affect blood sugar—it significantly increases the risk of heart disease, kidney problems, and metabolic complications. Plus, it carries some of the highest per-patient healthcare costs worldwide.
Prevention isn't just smart medicine—it's essential.
The Science Behind the Success
Dr. Miguel Ruiz-Canela, Professor and Chair of Preventive Medicine at the University of Navarra and first author of the study, explained that "the Mediterranean diet acts synergistically to improve insulin sensitivity and reduce inflammation". When you add calorie control and physical activity to that foundation, those benefits multiply.
Co-author Miguel Martínez-González, professor at the University of Navarra and adjunct professor of nutrition at Harvard Chan School, noted: "In practical terms, adding calorie control and physical activity to the Mediterranean diet prevented around three out of every 100 people from developing diabetes—a clear, measurable benefit for public health".
What This Diet Actually Looks Like
The Mediterranean diet emphasizes:
- Plenty of fruits and vegetables – Fresh, colorful, and nutrient-dense
- Whole grains – Brown rice, whole wheat bread, quinoa
- Healthy fats – Extra-virgin olive oil and nuts
- Moderate amounts of fish and lean proteins – Especially fatty fish rich in omega-3s
- Limited dairy – Mostly yogurt and cheese in moderation
- Minimal red meat – Saved for occasional meals
The "smarter" version simply adds portion control (cutting about 600 calories daily) and regular movement—nothing extreme, just sustainable changes.
Building on Previous Success
The PREDIMED-Plus project builds on the original PREDIMED study (2003-2010), which demonstrated that following a Mediterranean diet enriched with extra-virgin olive oil or nuts reduces cardiovascular disease risk by 30%.
As Dr. Miguel Ángel Martínez-González explained: "Diabetes is the first solid clinical outcome for which we have shown—using the strongest available evidence—that the Mediterranean diet with calorie reduction, physical activity and weight loss is a highly effective preventive tool".
The research team hopes to demonstrate similar benefits for other major health challenges soon.
Real-World Application
Researchers emphasize that primary care providers can integrate this intervention as a sustainable, cost-efficient strategy to prevent type 2 diabetes on a large scale.
Dr. Ruiz-Canela summed it up perfectly: "It's a tasty, sustainable and culturally accepted approach that offers a practical and effective way to prevent type 2 diabetes—a global disease that is, to a large extent, avoidable".
The Challenges Ahead
While the results are incredibly promising, experts acknowledge there are barriers to implementation, especially in countries like the United States. These include:
- Food access and cost – Healthy foods aren't always affordable or available
- Built environments – Many neighborhoods lack safe places to walk or exercise
- Healthcare access – Not everyone can get nutrition counseling or professional support
Nevertheless, the study's success in Spain suggests that small, affordable changes could help fight diabetes and obesity worldwide.
What You Can Do Today
You don't need to wait for a formal program to start making changes. Here's how to apply these findings:
- Start with the basics – Focus on more vegetables, fruits, whole grains, and healthy fats
- Watch your portions – You don't need to count every calorie, but be mindful of serving sizes
- Move more – Even 30 minutes of brisk walking most days makes a difference
- Get support – Whether it's a doctor, nutritionist, or accountability buddy, having guidance helps
- Think long-term – This isn't a quick fix but a lifestyle that's meant to be enjoyable and sustainable
The Bottom Line
As Harvard's Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology, stated: "We're facing a global epidemic of diabetes. With the highest-level evidence, our study shows that modest, sustained changes in diet and lifestyle could prevent millions of cases of this disease worldwide".
The beauty of this research is that it proves prevention doesn't require deprivation. A Mediterranean-style diet is delicious, varied, and culturally rich. When combined with sensible portions and regular activity, it becomes one of the most effective tools we have against type 2 diabetes.
The message is clear: You have more control over your health than you might think. Small, consistent changes really do add up to major benefits—and that's not just hopeful thinking anymore. It's science.
Study Reference: Ruiz-Canela M, Corella D, Martínez-González MÁ, et al. Comparison of an energy-reduced Mediterranean diet and physical activity versus an ad libitum Mediterranean diet in the prevention of type 2 diabetes: A secondary analysis of a randomized controlled trial. Annals of Internal Medicine, August 2025.
Funding: European Research Council, Spanish National Institute of Health, Center for Biomedical Research Network (CIBER), and U.S. National Institute of Diabetes and Digestive and Kidney Diseases.
