How do studies measure adherence to the Mediterranean diet?

Several scales have been developed to assess individual and population adherence to the Mediterranean diet. The oldest of these is the Mediterranean Diet Scale (MDScale), developed in 1995 and revised since.^[1] The MDScale includes nine components, including beneficial components (i.e., vegetables, legumes, fruits and nuts, cereal, and fish), detrimental components (i.e., meat, poultry, and high-fat dairy products), ethanol intake, and the ratio of monounsaturated to saturated fatty acids. A score of 0 is assigned to someone whose consumption of beneficial components is below the median and a score of 1 is assigned when consumption is at or above the median. For detrimental components, this is reversed: scores of 0 and 1 are assigned when consumption is at or above the median and below the median, respectively. For ethanol, a value of 1 is assigned to men and women who consume 10–50 grams and 5–25 grams per day, respectively. The total score ranges from 0 (minimal adherence) to 9 (maximal adherence).^[1]

Other scales used internationally include the Mediterranean Food Pattern (MFP), the Mediterranean Diet Score (MD Score), the Short Mediterranean Diet Questionnaire (SMDQ), and the MedDiet Score.^[2] While each score differs in its particularities, all of them assess the intake of similar dietary components, and there appears to be a strong correlation among all the scales for measuring adherence to the Mediterranean diet.^[2]