Turkish Validity and Reliability of the Novel Validated Short Questionnaire for Assessing Adherence to the Mediterranean Diet and Nutritional Sustainability (MedQ-Sus): A Methodological Study

This study aims to validate the "Adherence of Mediterranean Diet and Nutritional Sustainability Questionnaire (MedQ-Sus)" and Filling the gap of a reliable, alcohol-free Mediterranean diet adherence tool for the Turkish population, considering the culture of low alcohol consumption. This study, which involved 290 participants aged 18 to 64, was conducted from October 2023 to May 2024. Content validity was assessed by an expert panel of 10 dietitian academics. The Davis method was applied to calculate the Content Validity Index (CVI). With CVI scores ranging from 0.8 to 1.0, none of the scale items were removed. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) served to assess the construct validity of the scale. The data were deemed appropriate for factor analysis, as indicated by the Kaiser-Meyer-Olkin (KMO) value of 0.905 and the Bartlett test results (χ² = 2426.436, p < 0.001). The single-factor structure of the scale was supported by the EFA results, with item factor loadings between 0.699 and 0.916. The Cronbach's α coefficient for the scale was found to be 0.954 in the internal consistency analyses. Positive item-total correlations were observed, and removing any item did not result in a significant increase in the Cronbach's α coefficient. As a result, it was concluded that the MedQ-Sus scale in its Turkish version is both valid and reliable. In Turkey, this scale can be utilized to evaluate the adherence of adults to the Mediterranean diet (MD) as well as their perception of nutritional sustainability. This study contributes to validating and establishing the reliability of a tool for measuring adherence to the MD among Turkish speakers.