Background: Obesity of children and adolescents has many different detrimental effects on body image, self-esteem (SE), depression and social isolation that are effective on their mental and social health. Objectives: The purpose of this study was to predict the quality of life (QOL) of obese and overweight girl students in Kermanshah city based on self-esteem, mental health and sleep quality variables. Methods: The research is a descriptive-analytical study that 419 obese and overweight girl students were selected using multi-stage cluster sampling and simple random sampling. For collection of needed data, several questionnaires including demographic, Rosenberg self-esteem, Goldberg general health, Pittsburgh sleep quality questionnaires and quality of life questionnaire related to word health organization were used. The BMI estimation method of the centers for disease control was used to determine overweight and obesity. Obtained data were analyzed using regression analysis in SPSS (Ver. 19) software environment. Results: The result of simple linear regression analysis showed that self-esteem, sleep quality and mental health variables, predict 0.11, 0.20, and 0.25 of the variance of total score for QOL, respectively. Multiple regression results indicated that mental health and sleep of quality variables had a significant effect on all dimensions and overall QOL scores (P < 0.01) simultaneously. The increasing effect of self-esteem on the dimensions of social relationships (P < 0.005), environmental health (P < 0.01) and overall QOL score (P < 0.01) was significant. According to obtained results, QOL has a direct and significant correlation with self-esteem (P < 0.01) mental health (P < 0.001) and, sleep quality (P < 0.001). Conclusions: Based on the obtained results, it can be concluded that mental health is the most important and influential factor on the quality of life of obese adolescent girls. The results of this study indicated that a planning is need to promote girls’ mental health.

Materials and Methods: This cross-sectional study was performed on 419 overweight and obese female high school students of Kermanshah in 2017 selected through two-stage cluster sampling. Data were collected using the standard questionnaires, including high school students' academic performance, Rosenberg Self-Esteem Scale, Goldberg's General Health Questionnaire, Littleton's Body Image Concern Inventory, physical activity subscale of Walker's Health-Promoting Lifestyle Profile II, and Pittsburgh Sleep Quality Index. Data analysis for structural equation modeling was performed using the IBM SPSS AMOS V. 21 software. Results: Self-esteem was found to have significant direct (β=0.412) and indirect (β=0.142) effects on academic performance, with direct effects being stronger (P<0.001). Body image, physical activity, general health, and sleep quality were found to have a significant direct effect on academic performance (P<0.05). However, these factors also had a significant indirect effect on this variable through the mediation of general health (P<0.05). Overall, these variables accounted for 35% of the variance in academic performance. Conclusion: Self-esteem, body image, physical activity, and sleep quality affect the academic performance of obese and overweight girl high school students not only directly but also indirectly through general health. The results of this study demonstrated the mediating role of mental health in predicting the academic performance of overweight and obese girl students.