Objectives This study aims to develop a dietary consciousness scale and examine its reliability and validity, as well as investigate the changes in psychological aspects that influence diet among Japanese adults during the COVID-19 pandemic and clarify its related factors.Methods An online survey was conducted from July 1, 2020 to July 3, 2020. Participants were adults aged between 20 and 69 years selected from 13 prefectures where the government declared the state of emergency from April to May 2020. All selected participants were shopping or cooking foods for more than 2 days a week at the time of the survey. A total of 2,299 participants were included in the analysis. Dietary consciousness was measured using 12 items, and the construct was examined using factor analysis. Cronbach's alpha was examined as an indicator of internal validity, and the criterion-referenced validity was confirmed using the Kruskal-Wallis test. To determine changes in dietary consciousness, we calculated total scores based on changes in each item of the Dietary Consciousness Scale as follows: no change (0 points), improved (+1 point), and worsening (-1 point). The associations between the changes in dietary consciousness and characteristics or socioeconomic factors of the participants were examined using the chi-squared test and residual analysis.Results Exploratory and confirmatory factor analyses demonstrated that a model consisting of two factors fitted the data (GFI = 0.958, AGFI = 0.938, CFI = 0.931, RMSEA = 0.066). Cronbach's alpha of the first factor (importance of diet) was 0.838 and 0.734 for the second factor (precedence of diet), and the reliability was confirmed at 0.828 for the entire scale. In the examination of criterion-related validity, the higher the stage of change, the higher the total score of the scale, and a significant difference was observed (P<0.001). The percentage of participants whose precedence worsened was higher than the importance. Significant differences were observed regarding gender, age group, marital status, employment status, household annual income, and income change during the COVID-19 pandemic considering changes in both the importance and precedence of diet. Those who were in the "worsening tendency" group in both the importance and precedence were men, 20-29 years old, unmarried, full-time employees, with a household income of 4-6 million yen during the past year.Conclusion During the COVID-19 pandemic, the precedence of diet worsened, compared to its importance, and men, young, or unmarried persons show a worsening of dietary consciousness.
Keywords: COVID-19; adults; dietary consciousness; factor structure; socioeconomic factors.