Diet plus exercise significantly reduced progression to diabetes in Spanish trial
For adults ages 55 to 75 years with metabolic syndrome and overweight or obesity, an intervention that included calorie reduction, the Mediterranean diet, and increased physical activity reduced diabetes incidence by 31% over six years compared to the Mediterranean diet alone.
An intensive diet and activity intervention significantly reduced progression to diabetes among older adults with metabolic syndrome compared to a Mediterranean diet alone, a recent trial found.
The trial, conducted at 23 centers across Spain, included 4,746 adults ages 55 to 75 years with metabolic syndrome and overweight or obesity but no cardiovascular disease or diabetes. They were randomized to an intervention with a reduced-calorie Mediterranean diet, increased physical activity, and behavioral strategies for reducing weight, or to a control group given education on adhering to a standard Mediterranean diet. Results were published by Annals of Internal Medicine on Aug. 26.
After a median of six years, diabetes had developed in 12.0% (95% CI, 11.9% to 12.1%) of the control group compared to 9.5% (95% CI, 9.4% to 9.5%) of the intervention group, for a reduction of 31% (95% CI, 18% to 41%), or 2.6 cases per 1,000 person-years. The intervention group had better adherence to the recommended diet, higher physical activity levels, and greater reductions in body weight and waist circumference, leading the study authors to conclude that the intervention was more effective than the Mediterranean diet alone at “reducing diabetes incidence in overweight/obese persons with metabolic syndrome.”
They noted that it's not possible to disentangle whether the findings were the result of the participants' greater weight loss, adherence, or physical activity or some combination of these factors. “Undoubtedly, weight loss, increased physical activity, and reduction in caloric intake represent greater challenges than only changing the dietary pattern,” said the authors, noting that because of this increased difficulty, the intervention group had more contact with study staff.
An accompanying editorial listed some challenges to applying these findings in the U.S., including that the price of extra-virgin olive oil has “nearly doubled since 2021 due to a combination of factors including climate change, rising production costs, supply chain disruptions, and now tariffs” and that the intervention's level of dietician services “may prove difficult to scale broadly in the United States given challenges with health care access and reimbursement for prevention services.” Still, the study serves as a reminder of “the tried-and-true effects of diet and physical activity” given current enthusiasm about weight loss medications, and it contributes to the strong evidence supporting the Mediterranean diet “as an optimal dietary patten for long-term health,” the editorial said.