Does the Advice to Eat a Mediterranean Diet With Low Carbohydrate Intake, Compared With a Low-fat Diet, Reduce Diabetes and Cardiovascular Disease?

Aim To compare advice on a Mediterranean diet with an energy content (E%) from carbohydrates between 25-30 E% with a traditional low-fat diet with 45-60 E% from carbohydrates.

Primary outcome Incidence of diabetes in non-diabetic patients or glycaemic control in patients with known diabetes.

Secondary outcome Recurrence of cardiovascular disease, blood lipid levels, quality of life by questionnaires.

Study design and study population This is a multi-centre, open, randomised study in patients treated for ischemic heart disease in Linköping, Norrköping and Jönköping hospitals. One thousand two hundred patients who are treated at the cardiac rehabilitation units will be consecutively recruited during three years. The patients will be randomised 1:1 to be given advice on a 1) Mediterranean diet with an energy content (E%) from carbohydrates between 25-30% or to 2) a traditional low-fat diet with 45-60 E% from carbohydrates. All eligible patients will be asked if they want to participate and provided with written information about the study when they are discharged from the hospital after treatment for ischemic heart disease. The decision to participate or not will be given at the following outpatient treatment at the cardiac rehabilitation unit. When the signed informed consent to participate in the study has been provided, the patient will be randomised to advice of either of the two dietary regimes.