Development and Application of Web-Based Dietary Evaluation System Using Food Frequency Questionnaire for Korean Adolescents

Abstract

We previously developed a dish-based semi-quantitative food frequency questionnaire (FFQ) for Korean adolescents and the developed FFQ’s reliability and validity was found reasonable. The objective of the current study was to construct web-based dietary evaluation system applying the FFQ for Korean adolescents and examine its applicability in the context of reliability and validity. A web-based dietary evaluation system was designed in a comprehensive approach, incorporating not only dietary data survey but also up-to-date nutrition information and individualized eating behavior guidelines. A convenience sample of 50 boys and girls aged 12-18 years agreed in the study participation and completed the FFQ twice and 3 days of dietary recall on the developed website during a two-month period. The FFQ’s reliability and validity was examined using correlation and cross classification analysis. We also measured participants’ subjective levels of the web site’s usability, visual effect, understanding, and familiarity. Spearman correlation coefficients for reliability ranged from 0.74(for vitamin A) to 0.94(for energy). From cross-classification analyses, the proportion of subjects in the same intake quartile was highest for energy(82.0%) and lowest for vitamin A(56.0%). With regard to validity analysis, Spearman correlation coefficients ranged from 0.27(for PUFA) to 0.79 (for energy). The proportions of subjects in the opposite categories between the first FFQ and 3-day diet recall data were generally low from 0.00% (for fat) to 36.2% (for sodium). Average subjective levels of the website’s usability, visual effect, understanding, and familiarity were all found over 4 points out of 5 points. The developed web-based dietary evaluation system can serve as a valid and attractive tool for administering FFQ to Korean adolescents.