The Combined Effect of the Mediterranean Diet and Physical Activity on the Components of Metabolic Syndrome in Adults: A Systematic Review of Randomised Controlled Trials

Metabolic syndrome (MetS) is a global public health challenge, characterized by the coexistence of cardiometabolic risk factors such as abdominal obesity, dyslipidaemia, hypertension, and insulin resistance. Non-pharmacological strategies, including the Mediterranean diet (MD) and physical activity (PA), have been widely studied for their potential to prevent and manage MetS. This systematic review aimed to synthesize the evidence on the combined effect of MD and PA on MetS components in adults, based on randomized controlled trials (RCTs). Twenty-two RCTs published between 2018 and 2024 were included, involving 11,478 participants. The interventions ranged from 8 weeks to 3 years and combined adapted or hypocaloric MDs with moderate-to-high-intensity PA, typically including walking, aerobic exercise, or high-intensity interval training (HIIT), performed 3 to 7 times per week. The combined interventions resulted in reductions in body weight (−2.5 to −7.2 kg), body mass index (−0.7 to −2.2 kg/m2), waist circumference (−5.1 to −7.8 cm), and blood pressure (up to −9.0 mmHg systolic and −6.7 mmHg diastolic). Improvements in HDL cholesterol, triglyceride levels, and insulin sensitivity were also observed. These findings suggest that integrated interventions based on the Mediterranean lifestyle are effective in reducing MetS components and may support future public health strategies.