Systematic Review of the Mediterranean Diet for Long-Term Weight Loss

Background: Although the long-term health benefits of the Mediterranean diet are well established, its efficacy for weight loss at ≥12 months in overweight or obese individuals is unclear. We therefore conducted a systematic review of randomized controlled trials (RCTs) to determine the effect of the Mediterranean diet on weight loss and cardiovascular risk factor levels after ≥12 months.

Methods: We systematically searched MEDLINE, EMBASE, and the Cochrane Library of Clinical Trials for RCTs published in English or French and with follow-up ≥12 months that examined the effect of the Mediterranean diet on weight loss and cardiovascular risk factor levels in overweight or obese individuals trying to lose weight.

Results: Five RCTs (n = 998) met our inclusion criteria. Trials compared the Mediterranean diet to a low-fat diet (4 treatment arms), a low-carbohydrate diet (2 treatment arms), and the American Diabetes Association diet (1 treatment arm). The Mediterranean diet resulted in greater weight loss than the low-fat diet at ≥12 months (range of mean values: -4.1 to -10.1 kg vs 2.9 to -5.0 kg), but produced similar weight loss as other comparator diets (range of mean values: -4.1 to -10.1 kg vs -4.7 to -7.7 kg). Moreover, the Mediterranean diet was generally similar to comparator diets at improving other cardiovascular risk factor levels, including blood pressure and lipid levels.

Conclusion: Our findings suggest that the Mediterranean diet results in similar weight loss and cardiovascular risk factor level reduction as comparator diets in overweight or obese individuals trying to lose weight.