Despite the fact that the dietary habits of adolescents have a multi-faceted impact on their personal health, future well-being, and the food ecosystem, the importance of this issue is not adequately recognized. Thus, this study aims to analyze the relationship between food literacy and healthy eating behavior, sustainable eating behavior among adolescents, considering the impact of dietary habits on health, future health, and the food ecosystem. The research findings confirm that food nutrition knowledge, food-related relational competence, and food-related self-regulation have a positive impact on healthy eating behavior. Additionally, food-related relational competence and understanding of the food system influence the intention for sustainable eating behavior. Furthermore, the presence or absence of culinary major was found to moderate the relationship between various aspects of food literacy, including food and nutrition knowledge, cooking skills, food-related competence, and healthy dietary behaviors. Through this study, the relationship between food literacy, healthy eating behavior, and the intention for sustainable eating behavior among adolescents was analyzed, considering various aspects and factors that influence dietary habits. The implications of this study shed light on the importance of improving adolescent dietary habits and provide insights for policy-making and educational strategies.