The Mediterranean diet, already famous for doing nice things for your heart and metabolism, has apparently been coasting on its laurels. A major Spanish clinical trial now suggests that pairing it with three upgrades - eating fewer calories, moving more, and getting professional weight-loss support - makes it work even better against type 2 diabetes.
The PREDIMED-Plus trial, the largest nutrition trial ever conducted in Europe, found that this more structured version of Mediterranean living reduced the risk of developing type 2 diabetes by 31%. The project involved the University of Navarra and more than 200 researchers from 22 other Spanish universities, hospitals, and research centers, operating across 100 primary care centers within Spain's National Health System.
PREDIMED-Plus started in 2013 after the University of Navarra snagged an Advanced Grant from the European Research Council worth over €2 million. By 2016, total funding had ballooned to more than 15 million euros, mostly from the Carlos III Health Institute and the Center for Biomedical Research Network through its obesity, epidemiology, and diabetes areas.
The results, published in Annals of Internal Medicine, come from 4,746 adults aged 55 to 75. All had overweight or obesity and metabolic syndrome, but no diabetes or cardiovascular disease at the start. Researchers followed them for six years to see if a more intense Mediterranean-based lifestyle plan could outdo the traditional version.
One group followed a calorie-reduced Mediterranean diet (about 600 kcal fewer per day), added moderate physical activity (brisk walking, strength and balance training), and got professional guidance. The comparison group just ate a traditional Mediterranean diet without calorie restriction or exercise advice. The difference was striking: the intervention group was 31% less likely to develop type 2 diabetes.
They also lost more weight and belly fat. On average, the intervention group shed 3.3 kg and reduced waist circumference by 3.6 cm. The control group lost only 0.6 kg and trimmed 0.3 cm from their waistlines. Researchers estimate the program prevented about three cases of type 2 diabetes for every 100 participants.
"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," said Miguel Ángel Martínez-González, Professor of Preventive Medicine and Public Health at the University of Navarra and Adjunct Professor of Nutrition at Harvard University. "Applied at scale in at-risk populations, these modest and sustained lifestyle changes could prevent thousands of new diagnoses every year."
Type 2 diabetes is one of the world's fastest growing chronic diseases. The International Diabetes Federation estimates over 530 million people worldwide now live with diabetes. Spain has about 4.7 million adults with diabetes, one of the highest rates in Europe. Across Europe, more than 65 million people have diabetes; in the U.S., about 38.5 million are affected. Experts stress that prevention is essential because type 2 diabetes raises the risk of cardiovascular, kidney, and metabolic complications.
"The Mediterranean diet acts synergistically to improve insulin sensitivity and reduce inflammation. With PREDIMED-Plus, we demonstrate that combining calorie control and physical activity enhances these benefits," said Miguel Ruiz-Canela, Chair of Preventive Medicine at the University of Navarra and first author. "It is 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."
Related PREDIMED-Plus research continues to pile on. A body composition analysis in JAMA Network Open found the energy-reduced diet plus exercise helped reduce total and visceral fat while slowing age-related loss of lean mass. A 2026 study in BMC Cardiovascular Disorders reported that replacing sedentary time with physical activity was linked to favorable five-year changes in a heart stress marker.
A 2025 review in Cardiovascular Research called the Mediterranean diet one of the best studied dietary patterns for cardiovascular prevention. Meanwhile, a 2026 analysis from the original PREDIMED trial highlighted that participants with higher intake of extra virgin olive oil had lower cardiovascular risk, while common olive oil showed weaker associations. Message: fat quality matters.
An accompanying editorial by Sharon J. Herring and Gina L. Tripicchio of Temple University praised the intervention's clinical importance but cautioned that bringing it outside the Mediterranean region, especially the U.S., faces barriers like unequal access to healthy food, urban environments that discourage physical activity, and limited access to professional guidance. They argued for public policies to create healthier environments - a timely point as obesity and diabetes drugs grab headlines.
The PREDIMED-Plus project (2013-2024) builds on the earlier PREDIMED study (2003-2010), which showed that a Mediterranean diet enriched with extra virgin olive oil or nuts reduced cardiovascular disease risk by 30%. Researchers say the updated strategy could be used by primary care providers as a sustainable way to prevent type 2 diabetes at scale, relying on familiar foods, moderate activity, gradual weight loss, and professional support - no extreme dieting required.