This study used TEXTOM for a total of 4 years, 2 years before and after, as of January 19, 2020, when the domestic confirmed cases of COVID-19 were officially announced, targeting Naver, Daum, Google, YouTube, and Twitter. By analyzing changes in adolescents' interest and awareness of their dietary habits, we aimed to create an opportunity to develop a dietary education program to provide proper dietary education. The results obtained through this study are as follows. First, the keywords with the highest co-occurrence before COVID-19 were 'nutrition' and 'counseling', and the next keywords were 'nutrition' and 'education'. After COVID-19, the order was 'nutrition', 'education', 'food' and 'safety'. Second, the results of co-occurrence frequency network analysis showed that there was high interest in nutrition and counseling regardless of COVID-19, and that interest in safety and health increased further after COVID-19. Third, through cluster formation through CONCOR analysis, before COVID-19, it was categorized into 'diet and physical activity', 'skin and disease', 'health and food', and 'nutrition and intake', and after COVID-19, it was categorized into 'nutrition, intake and COVID-19', 'diet and physical activity', 'skin and disease', and 'circadian rhythm imbalance and disease'. Fourth, as a result of the diet-related keyword cluster analysis network, before COVID-19, keywords in the 'eating and physical activity' group were strongly connected to keywords in the 'health and food' and 'nutrition and intake' groups, and after COVID-19, 'diet' Keywords in the 'and physical activity' group were strongly connected to keywords in the 'nutrition, intake, and COVID-19' group.