Effectiveness of interventions applicable to primary health care settings to promote Mediterranean diet or healthy eating adherence in adults: A systematic review

Objective: To evaluate the effects on healthy eating or the Mediterranean diet adherence achieved by interventions suitable for implementation in primary care settings.

Methods: Medline (PubMed) and The Cochrane Library bibliographic searches retrieved randomized controlled trials published in English or Spanish, January 1990-January 2013. The inclusion criteria were adult population, >3 months follow-up, and interventions suitable for primary care settings. Exclusion resulted if studies focused exclusively on weight loss or did not analyze food intake (fats, fruits and vegetables--F&V, fiber) or Mediterranean diet adherence. Validity (risk of bias) was independently evaluated by two researchers; discrepancies were reviewed until a consensus was reached.

Results: Of the 15 included articles (14 studies), only 3 studies surpassed 12-months follow-up. Ten interventions emphasized healthy nutrition (n = 9948); 4 added activity levels (n = 3816). Six trials included participants with cardiovascular risk; 7 were community-based; 1 focused on women with cancer. Eleven studies showed 9.7% to 59.3% increased F&V intake with counseling interventions, compared to baseline (-13.3% to 27.8% in controls). Seven studies reported significant differences between intervention and control groups.

Conclusion: Nutritional counseling moderately improves nutrition, increases intake of fiber, F&V, reduces dietary saturated fats, and increases physical activity. Studies with longer follow-up are needed to determine long-term effects, cardiovascular morbidity, and mortality.