Validation of a short questionnaire to record adherence to the Mediterranean diet: An Italian experience

Background and aims: A greater adherence to the Mediterranean diet has been associated with a reduced risk of major chronic diseases and cancer. The aim of the study was to assess the validity of a new short self-administered 15-item questionnaire (QueMD) to measure adherence to the Mediterranean diet in Italy.

Methods and results: Four-hundred and eighty three participants to cancer-screening programmes at the European Institute of Oncology, Milan (Italy) were invited to join this study. Those interested compiled the QueMD and a validated Food Frequency Questionnaire (FFQ) reporting their usual food consumption during the previous six months. We derived the alternate Mediterranean score (aMED) from both questionnaires with values ranging from 0 (minimal adherence) to 9 (maximal adherence). Complete dietary data were available for 343 individuals (participation rates 71.0%). Spearman correlation coefficient between the responses to the 15 questions of the QueMD and corresponding food intake derived from the FFQ ranged from 0.15 to 0.84. A moderate correlation was found between the aMED scores calculated from the QueMD and the FFQ (intraclass correlation coefficient 0.50; 95% CI, 0.42-0.58), while agreement between the two instruments was only poor to fair for 7 of the 9 single items composing the aMED score, with values ranging from 53.0% for wholegrain products to 79.5% for fruits.

Conclusion: This new self-administered 15-item questionnaire could be a useful tool to assess adherence to the Mediterranean diet in the Italian population.