The information provided by food labels is essential for health risk assessment, enabling consumers to make informed choices that help them maintain good health and reduce diet-related disease risks. This study, based on Schwartz's social–psychological model of knowledge, attitude, and behavior, explores how nutrition labeling on packaged juice drinks affects adolescents' knowledge, attitudes, and behaviors in Taiwan. Using a questionnaire survey method, data were collected from teenagers who had purchased packaged juice drinks from convenience stores in Taipei. The sample was analyzed with SPSS for Windows 26.0 using descriptive statistics, chi-square tests, independent sample t-tests, one-way ANOVA, and Scheffé post hoc comparisons. The findings reveal significant differences in knowledge, attitudes, and behaviors regarding food labeling among adolescents of different genders. A strong correlation was found between adolescents’ knowledge, attitudes, and behaviors towards juice drink labeling. Background variables significantly predicted these factors. These results suggest a critical role of gender and background in shaping adolescents' engagement with nutritional labels. Incorporating these insights into dietary education policies could enhance health education programs' effectiveness. Tailoring educational strategies to specific needs based on gender and background can improve health outcomes and encourage healthier dietary choices among adolescents. This highlights the importance of integrating comprehensive nutritional label education into school curriculums and public health initiatives to foster a well-informed younger generation capable of making better dietary decisions.