A study testing the usefulness of a dish-based food-frequency questionnaire developed for epidemiological studies in Korea

The purpose of the present study was to test the usefulness of dish items selected in developing a dish-based FFQ (DFFQ) to be used for epidemiological studies in Korea. The dietary data of 6817 subjects from the 2001 Korean National Health and Nutrition Examination Survey were used for the analysis. The 24h recall method was employed for the dietary survey. Initially, ninety-five dish items were selected in developing the DFFQ based on consumption frequency, contribution of selected nutrients and coverage of between-person variations. The usefulness of the selected ninety-five dish items was tested based on their degree of contribution in supplying nutrients in the cumulative percentage contribution (cPC), as well as on their degree of explanation for between-person variation in the cumulative regression coefficient (cMRC). According to the results, the ninety-five selected dish items accounted for an average of 92.3 % of seventeen nutrients consumed by the study subjects based on cPC estimation. The top twenty items among the ninety-five dish items covered 70 to 91 % of the between-person variation for the seventeen nutrients based on cMRC estimation. Thus, the results suggest that the ninety-five items would be useful in developing a FFQ for use in epidemiological studies of Koreans, within less than 10% underestimation.