RESUMEN
PURPOSE: Adherence to a healthy dietary pattern positively influences clinical outcomes in cardiovascular prevention, but long-term adherence is difficult to maintain. We evaluated 5-year changes in dietary habits, adherence achieved, and its maintenance in a cohort of coronary patients from the CORDIOPREV study. METHODS: 1002 coronary patients were randomized to a Mediterranean diet (n = 502) or a low-fat diet (n = 500) and received individual-group-telephone visits and personalized dietary advice. A validated food-frequency questionnaire, a 14-point Mediterranean diet adherence screener, and a 9-point low-fat diet adherence score were used. Dietary adherence was categorized into Low, Medium, and High Adherence. Changes in nutrient intake, food consumption, and adherence were analyzed on a yearly basis. The maintenance of long-term dietary adherence was evaluated using data after the first year and fifth year. RESULTS: From baseline to 5 years, significant increases were observed in overall dietary adherence (Mediterranean diet from 8.9 to 11.4; low-fat diet from 3.9 to 7.1) and in the percentage of patients considered High Adherence (Mediterranean diet from 41 to 89%; low-fat diet from 4 to 67%). When we evaluated the maintenance of adherence, patients considered Low and Medium Adherence at 1 year increased their adherence at the 5 years with both diets and patients considered High Adherence maintained their adherence with a Mediterranean diet, but decreased their adherence with a low-fat diet. CONCLUSIONS: A comprehensive dietary intervention results in an overall long-term improvement and maintenance of adherence to the Mediterranean and low-fat diets. In our population, the Mediterranean diet group achieved a high level of adherence in the short term which was maintained in the long term.
Asunto(s)
Dieta con Restricción de Grasas , Dieta Mediterránea , Ingestión de Alimentos , Ingestión de Energía , Conducta Alimentaria , HumanosRESUMEN
BACKGROUND: Dietary intervention success requires strong participant adherence, but very few studies have examined factors related to both short-term and long-term adherence. A better understanding of predictors of adherence is necessary to improve the design and execution of dietary intervention trials. This study was designed to identify participant characteristics at baseline and study features that predict short-term and long-term adherence with interventions promoting the Mediterranean-type diet (MedDiet) in the PREvención con DIeta MEDiterránea (PREDIMED) randomized trial. METHODS: Analyses included men and women living in Spain aged 55-80 at high risk for cardiovascular disease. Participants were randomized to the MedDiet supplemented with either complementary extra-virgin olive oil (EVOO) or tree nuts. The control group and participants with insufficient information on adherence were excluded. PREDIMED began in 2003 and ended in 2010. Investigators assessed covariates at baseline and dietary information was updated yearly throughout follow-up. Adherence was measured with a validated 14-point Mediterranean-type diet adherence score. Logistic regression was used to examine associations between baseline characteristics and adherence at one and four years of follow-up. RESULTS: Participants were randomized to the MedDiet supplemented with EVOO (n = 2,543; 1,962 after exclusions) or tree nuts (n = 2,454; 2,236 after exclusions). A higher number of cardiovascular risk factors, larger waist circumference, lower physical activity levels, lower total energy intake, poorer baseline adherence to the 14-point adherence score, and allocation to MedDiet + EVOO each independently predicted poorer adherence. Participants from PREDIMED recruiting centers with a higher total workload (measured as total number of persons-years of follow-up) achieved better adherence. No adverse events or side effects were reported. CONCLUSIONS: To maximize dietary adherence in dietary interventions, additional efforts to promote adherence should be used for participants with lower baseline adherence to the intended diet and poorer health status. The design of multicenter nutrition trials should prioritize few large centers with more participants in each, rather than many small centers. TRIAL REGISTRATION: This study was registered at controlled-trials.com (http://www.controlled-trials. com/ISRCTN35739639). International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005. TRIAL DESIGN: parallel randomized trial.