Indexes for Assessing Adherence to a Mediterranean Diet from Data Measured through Brief Questionnaires: Issues Raised from the Analysis of a Greek Population Study123

Background: Adherence to a Mediterranean diet (MD) has been quantified through various indexes that rely on full-length questionnaires, but their application in data collected with brief questionnaires has not been systematically investigated. Objective: We aimed to evaluate the ability of the commonly used MD score (MDS) to classify individuals according to their adherence to an MD when applied to data collected with brief