This research aims to see how adolescents' knowledge and attitudes about balanced nutrition are related to their eating behavior. Adolescents are the age group most vulnerable to changes in unhealthy eating habits, which can have a major impact on important aspects of their health. This research involved 160 junior high school students aged 12 to 17 years. Guidelines for knowledge of balanced nutrition (PUGS) as well as eating attitudes and behaviors are the topics of the Nutritional Literacy Survey. Based on the investigation, it is known that 66.9% are in the middle adolescence group (aged 14–17 years). Most respondents had moderate nutritional knowledge with a percentage of 69.4%, a negative attitude percentage of 55.6%, and eating behavior was also in the moderate category at 65.6%. The results of research using bivariate analysis show that the relationship between knowledge and adolescent eating behavior has a p-value of 0.114 (p > 0.05) and the relationship between attitude and adolescent eating behavior has a p-value of 0.108 (p > 0.05), so it can be concluded that there is no relationship between knowledge and attitudes towards the balanced nutritional eating behavior of adolescents. The significance of this research lies in the importance of integrating nutrition education into school programs and curricula to increase nutrition knowledge in adolescents, such as nutrition with science, technology, engineering, and mathematics (STEM). Additionally, educational programs that focus on sustainable development and health awareness may be effective in encouraging healthy eating habits in this age group.