title: Calibration of a food frequency questionnaire in Koreans.
abstract: The current trend of changes in nutrient intakes may have some relationship with the increase in the occurrence of degenerative diseases in the Korean population. To date, a calibrated food frequency questionnaire (FFQ) has not been developed that can be further used for large-scale epidemiological research in Koreans aged 40 and older. This study was undertaken to develop and calibrate an FFQ in Koreans. A total of 144 Koreans aged 40 years and above participated in the first phase, which was conducted using the three-day dietary record method. One hundred and thirty-eight of those who completed the first phase were then interviewed to test FFQ against dietary records as a reference. The mean absolute nutrient intakes estimated by the dietary records were statistically compared with those estimated by the FFQ using paired t-tests. The mean values from the FFQ differed at most by 14% from those of the dietary records for all nutrients with the exception of vitamin A. Spearman rank-order correlation coefficients and cross-classification were also calculated. The energy-adjusted and corrected correlations for attenuation varied from 0.36 to 0.82. The degree of good agreement by cross-classification between the dietary records and the FFQ ranged from 67% to 90%. The newly developed FFQ can be used as a dietary assessment tool to measure usual nutritional status of Koreans aged 40 years and older. Furthermore, this study demonstrates that the FFQ also provides a more labour-efficient tool that is easier to use than any of the commonly used methods for large-scale epidemiological studies of the relationships between nutrition and diseases in Koreans.
mesh_terms: D000328:Adult; D000368:Aged; D002138:Calibration; D004032:Diet / Q000706:statistics & numerical data*; D015930:Diet Records; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D007723:Korea; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*