Abstract

Type 2 diabetes mellitus (DM2) is a growing global health issue, and dietary interventions play a significant role in its prevention and management. The Mediterranean diet (MedDiet), characterized by high consumption of fruits, vegetables, whole grains, and healthy fats, has been proposed as an effective dietary strategy for reducing the incidence of DM2 and improving glycemic control. This study aimed to evaluate the effectiveness of the MedDiet in reducing DM2 incidence in high-risk individuals compared with a low-fat diet, and to assess its impact on glycemic control parameters, including fasting blood glucose and glycated hemoglobin, in diabetic patients. A systematic search was conducted using online scientific databases, including English language studies published from inception to February 15, 2025, that reported on incident DM2 cases and/or glycemic control in patients following a MedDiet compared with low-carbohydrate or low-fat diets (Low-Crab). The MedDiet significantly reduced the risk of DM2, with an odds ratio (OR) of 0.50 (95% CI: 0.27-0.93; p = 0.0007), indicating a 50% lower risk compared with a low-fat diet. Regarding glycemic control, the MedDiet demonstrated significant improvement compared with a Low-Crab (mean difference = 0.93; 95% CI: -0.74, 2.59; p = 0.02). However, when compared with a low-fat diet, no significant difference in glycemic control was observed (mean difference = -0.94; 95% CI: -16.88, 15.01; p = 0.46). Substantial heterogeneity was noted across studies. This meta-analysis supports the MedDiet as an effective intervention for reducing the risk of DM2 and improving glycemic control in diabetic patients. Nevertheless, further large-scale, well-designed studies are required to validate these findings and address the observed heterogeneity.

Key words: Mediterranean diet, type 2 diabetes, glycemic control, low-fat diet, low-carbohydrate diet.