Introduction: Eating disorders are prevalent mental health issues among today's teenagers, resulting in dietary instability and severe impacts on the affected individual's physical health mental and social functioning.

Methods: In this semi-experimental study, 40 teenage girls with eating disorders participated. They were then randomly divided into two groups: case and control. The self-care behavior questionnaire and nutritional attitude questionnaire were utilized to measure variables in these individuals. To analyze the effectiveness of rational-emotional treatment on improving self-care activities and nutritional performance, multivariate covariance analysis was employed.

Results: The results indicate that rational-emotional therapy was successful in promoting adherence to the prescribed diet, abstaining from smoking, and reducing the impact of stressful factors on adolescents with eating disorders (P˂ 0.05). However, this intervention did not show efficacy in improving adherence to the prescribed medication regimen and compliance with physical activity (P˃ 0.05). Additionally, rational-emotional therapy was effective in influencing eating habits and promoting oral control among adolescents with eating disorders (P˂ 0.05), but did not significantly impact on desire to eat (P˃ 0.05).

Conclusion: Rational-Emotional Therapy has proven to be effective for improving in the most of the self-care activities and nutritional performance of teenage girls with eating disorders.