A systematic review and meta-analysis of nine randomized clinical trials (RCTs) found that Mediterranean diet (MedDiet)-based interventions in children and adolescents were associated with significant reductions in systolic blood pressure (SBP), triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), as well as increases in high-density lipoprotein cholesterol (HDL-C). The studies, involving 577 participants aged 3–18 years, showed that MedDiet interventions led to a mean SBP reduction of -4.75 mm Hg, a TG reduction of -16.42 mg/dL, a TC reduction of -9.06 mg/dL, and an LDL-C reduction of -10.48 mg/dL, along with an HDL-C increase of 2.24 mg/dL. No significant associations were found for diastolic blood pressure (DBP), glucose, insulin, or homeostatic model assessment for insulin resistance (HOMA-IR). The quality of evidence was moderate for most biomarkers but low for SBP and serum glucose. The findings suggest that MedDiet-based interventions may be useful for improving cardiometabolic health in children and adolescents. However, the results should be interpreted with caution due to the limited number of RCTs and potential biases. The study highlights the importance of promoting healthy eating habits in youth to reduce cardiometabolic risks.A systematic review and meta-analysis of nine randomized clinical trials (RCTs) found that Mediterranean diet (MedDiet)-based interventions in children and adolescents were associated with significant reductions in systolic blood pressure (SBP), triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), as well as increases in high-density lipoprotein cholesterol (HDL-C). The studies, involving 577 participants aged 3–18 years, showed that MedDiet interventions led to a mean SBP reduction of -4.75 mm Hg, a TG reduction of -16.42 mg/dL, a TC reduction of -9.06 mg/dL, and an LDL-C reduction of -10.48 mg/dL, along with an HDL-C increase of 2.24 mg/dL. No significant associations were found for diastolic blood pressure (DBP), glucose, insulin, or homeostatic model assessment for insulin resistance (HOMA-IR). The quality of evidence was moderate for most biomarkers but low for SBP and serum glucose. The findings suggest that MedDiet-based interventions may be useful for improving cardiometabolic health in children and adolescents. However, the results should be interpreted with caution due to the limited number of RCTs and potential biases. The study highlights the importance of promoting healthy eating habits in youth to reduce cardiometabolic risks.