Incorporation of an Online Self-Administered Dietary Behavior Survey into the 10th Cycle of the Korea National Health and Nutrition Examination Survey (2025-2027).

Objectives: The Korea National Health and Nutrition Examination Survey (KNHANES) introduced self-administered online surveys to adapt to changing survey environments, improve participant convenience, and ensure continuous data collection during infectious disease outbreaks. This report describes major modifications to the dietary behavior survey in the 10th cycle of the KNHANES (2025-2027) following the implementation of the new online self-administered survey method. Methods: Existing dietary behavior questions were revised to improve respondent comprehension and self-response accuracy, and new items were developed to address topics relevant to policy planning and research guidance. All revised and new items underwent cognitive and validity testing and were finalized following expert consultation. Results: Items regarding breakfast frequency, dietary supplement use, nutrition education or counseling, nutrition labeling, and fruit intake frequency were retained but revised to fit the self-administered format with added explanatory notes and visual aids. Items related to lunch and dinner frequency, meal companions, vegetable intake, and current supplement type and dose were excluded because of limited utility and to reduce the risk of response bias. The dining-out frequency question was deleted because of low respondent comprehension and questionable validity. Three new questions regarding restaurant dining frequency; frequency of meat, fish, eggs, and legume consumption; and frequency of milk and dairy product consumption were introduced. Conclusions: The 10th KNHANES Dietary Behavior Survey was redesigned to facilitate online self-administration. Concurrently, questions were modified or added to address social and environmental changes and to enhance the applicability, continuity, and representativeness of future national dietary surveys.