OBJECTIVE: To assess the effectiveness of an intervention aimed to increase adherence to a Mediterranean diet. DESIGN: A 12-month assessment of a randomized primary prevention trial. SUBJECTS/SETTINGS: One thousand five hundred fifty-one asymptomatic persons aged 55 to 80 years, with diabetes or > or =3 cardiovascular risk factors. INTERVENTION: Participants were randomly assigned to a control group or two Mediterranean diet groups. Those allocated to the two Mediterranean diet groups received individual motivational interviews every 3 months to negotiate nutrition goals, and group educational sessions on a quarterly basis. One Mediterranean diet group received free virgin olive oil (1 L/week), the other received free mixed nuts (30 g/day). Participants in the control group received verbal instructions and a leaflet recommending the National Cholesterol Education Program Adult Treatment Panel III dietary guidelines. MAIN OUTCOME MEASURES: Changes in food and nutrient intake after 12 months. STATISTICAL ANALYSES: Paired t tests (for within-group changes) and analysis of variance (for between-group changes) were conducted. RESULTS: Participants allocated to both Mediterranean diets increased their intake of virgin olive oil, nuts, vegetables, legumes, and fruits (P<0.05 for all within- and between-group differences). Participants in all three groups decreased their intake of meat and pastries, cakes, and sweets (P<0.05 for all). Fiber, monounsaturated fatty acid, and polyunsaturated fatty acid intake increased in the Mediterranean diet groups (P<0.005 for all). Favorable, although nonsignificant, changes in intake of other nutrients occurred only in the Mediterranean diet groups. CONCLUSIONS: A 12-month behavioral intervention promoting the Mediterranean diet can favorably modify an individual's overall food pattern. The individual motivational interventions together with the group sessions and the free provision of high-fat and palatable key foods customary to the Mediterranean diet were effective in improving the dietary habits of participants in this trial.

Evaluar la eficacia de una intervención dirigida a aumentar la adhesión a la dieta mediterránea. Para ello se realiza una evaluación de 12 meses en un ensayo aleatorizado de prevención primaria. Para ello se emplearon mil quinientas cincuenta y una personas asintomáticas de entre 55 y 80 años, con diabetes y 3 factores de riesgo cardiovascular. Los participantes fueron asignados aleatoriamente a un grupo de control o dos grupos de dieta mediterránea.. Un grupo recibió la dieta mediterránea sin aceite de oliva virgen (1 L / semana), el otro recibió frutos secos (30 g / día). Los participantes en el grupo control recibireon instrucciones verbales y un folleto recomendando por el National Cholesterol Education Program Adult Treatment Los cambios en la alimentación y la ingesta de nutrientes después de 12 meses. Los valores asignados a las dos dietas mediterráneas incrementaron su consumo de aceite de oliva virgen, frutos secos, verduras, legumbres y frutas (P <0,05). Los participantes en los tres grupos disminuyeron su ingesta de carnes y pastas, pasteles y dulces (P <0,05 para todos). Una intervención en el comportamiento de 12 meses en la promoción de la dieta mediterránea puede modificar favorablemente el patrón alimenticio de un individuo. Las intervenciones individuales de motivación, junto con las sesiones de grupo y la libre prestación de alimentos clave de alto contenido en grasa y eran efectivos para mejorar los hábitos alimenticios de los participantes en este ensayo.