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

•Nutritional counseling achieves moderate improvement in dietary habits.•The long-term effect of counseling interventions has not been established.•Interventions with multiple elements are more effective than counseling alone.•Intensive or aimed to patients with greater risk interventions are more effective.

ObjectiveTo evaluate the effects on healthy eating or the Mediterranean diet adherence achieved by interventions suitable for implementation in primary care settings.MethodsMedline (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.ResultsOf 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.ConclusionNutritional 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.