PREDIMED-Plus Trial Shows Modified Mediterranean Diet Reduces Diabetes Risk by 31%

The Study and Its Core Findings

A major Spanish study, PREDIMED-Plus, showed that a modified Mediterranean diet with calorie reduction, moderate exercise, and weight-loss support lowered type 2 diabetes risk by 31% over six years. Led by the University of Navarra and involving 4,746 adults aged 55–75 with metabolic syndrome, the trial found participants in the intervention group lost 3.3 kg and reduced waist size by 3.6 cm compared to a control group. Published in Annals of Internal Medicine, the results show promise as a preventive measure. The project, which started in 2013 and got €15 million from the Carlos III Health Institute and other Spanish research groups, shows a long-term focus on improving dietary strategies. The study’s design, combining structured physical activity and personalized coaching, marks a shift toward more holistic, patient-centered approaches to managing chronic diseases. Researchers said the success depended on a mix of dietary changes, regular exercise, and behavioral counseling, which addressed both physical and mental barriers to health improvements.

“Medication isn’t the only path, but lasting changes need supportive policies.”

Historical Context and Scientific Evolution

The Mediterranean diet’s reputation for heart benefits goes back to the 1950s, but its use for diabetes prevention gained attention with the 2003 PREDIMED study, which cut cardiovascular disease risk by 30%. PREDIMED-Plus builds on that by adding calorie control and structured physical activity. A 2025 Cardiovascular Research review highlighted the diet’s role in reducing cardiometabolic risks, citing studies like PREDIMED and Lyon Diet Heart Study. The study involved 22 Spanish institutions, including the University of Navarra, Hospital Clínic de Barcelona, University of Valencia, and IMIM-Hospital del Mar, showing a decades-long effort to refine dietary approaches. A 2021 Nutrients review noted the diet’s ability to reduce inflammation and improve insulin sensitivity, mechanisms that align with the observed diabetes risk reduction.

Limitations and Skepticism

While the results are encouraging, the study’s group—overweight adults with metabolic syndrome—may not represent the general population. Critics say the program’s success relies on sticking to the lifestyle changes, which is hard in real-world settings. For instance, a 2020 Nutrients study found that people stick to calorie-reduced diets by about half after 12 months without structured help, showing how important the coaching was. Sharon J. Herring and Gina L. Tripicchio of Temple University warn that scaling the program globally, especially in the U.S., needs addressing issues like food access and city design. ‘Medication isn’t the only path,’ they say, ‘but lasting changes need supportive policies.’ Also, the study used self-reported diet data, which could introduce errors affecting long-term results. A 2024 The Lancet study found low-income areas face 40% more trouble getting healthy food, stressing the need for policies to make the program accessible.

Expert Insights and Broader Trends

The study fits with a growing focus on prevention over treatment. A 2025 Cardiovascular Research review highlighted the Mediterranean diet’s role in reducing cardiometabolic risks, citing studies like PREDIMED and Lyon Diet Heart Study. A 2026 analysis from the original PREDIMED trial showed higher olive oil intake linked to lower cardiovascular risks, suggesting diet quality—not just quantity—matters. This challenges the idea that the diet is just about ‘eating more plants,’ adding complexity to its use. The findings also match the World Health Organization’s 2023 push for ‘dietary diversification’ to fight non-communicable diseases, putting the Mediterranean diet at the heart of global health strategies. A 2021 Nutrients review emphasized how polyphenols and omega-3s improve insulin sensitivity, mechanisms that may explain the diet’s effectiveness in diabetes prevention.

Implications for Global Health

Type 2 diabetes affects over 530 million people worldwide, making it a growing public health issue. The PREDIMED-Plus findings offer a scalable, cost-effective approach for at-risk groups. However, experts say while lifestyle changes can prevent thousands of cases yearly, they must be paired with policies tackling socioeconomic gaps. For example, a 2024 The Lancet study found low-income areas face 40% more barriers to healthy food, highlighting the need for subsidies or urban planning changes. As the U.S. deals with rising obesity and healthcare costs, the study’s focus on ‘tasty, sustainable’ interventions could reshape diabetes prevention plans. The next step may involve combining these strategies with new obesity drugs, ensuring a full approach to chronic disease management. However, the long-term effects of such mixes are still being studied, with ongoing trials looking at how lifestyle changes and medications work together. The study’s focus on older adults also raises questions about its use in younger people, suggesting a need for more research to find the best approaches for different age groups.