The Diet Quality Index-International (DQI-I): is it a useful tool to evaluate the quality of the Mediterranean diet?

The aim of this study was to assess whether the recently developed Diet Quality Index-International (DQI-I) could be used to evaluate diet quality of a Mediterranean population. A cross-sectional nutritional survey was carried out in the Balearic Islands (Spain) between 1999 and 2000. Dietary information (replicated 24 h recall and a food frequency questionnaire), and socio-demographic and lifestyle data were collected from a representative sample of the population (n 1200: 498 males and 702 females) aged 16-65 years (response rate 77.22 %). The DQI-I was developed according to the method defined by Kim et al. (2003), and focused on four major aspects of a high-quality diet (variety, adequacy, moderation and overall balance). The percentage of adherence to the Mediterranean dietary pattern (MDP) was also calculated and correlation analysis was carried out between the DQI-I score and the percentage of adherence to the MDP. The total score of the DQI-I reached 43 % of the possible score, indicating that the Balearic diet was a poor-quality diet. Correlation analysis between the DQI-I scores and adherence to the MDP showed that the DQI-I subcategories protein, iron and calcium adequacy were negatively correlated with the MDP. Furthermore, moderation in empty calorie food consumption and overall balance subcategories were not significantly correlated with the MDP. Due to some methodological factors and cultural biases, the proposed DQI-I scoring system is not useful to evaluate the quality of this Mediterranean-type diet. Further research is needed to develop a new diet quality index adapted to the MDP.