Background and Objectives: Obesity and overweight are considered as an undesirable prognosis for chronic physical illness. This study aimed to investigate the relationship between body mass index , perceived stress and health-related quality of life among male and female adolescents of Zanjan 2017.
Materials & Methods: During this descriptive- correlational study between the population of male and female students in Zanjan, using a stratified random sampling method,150 students (78 girls and 72 boys) were selected.The data were collected by tools of Cohen Perceived Stress, Quality of life and calculation of body mass index (BMI).Data were analyzed by SPSS statistical software ,using Pearson correlation and independent t test.
Results: Mean and standard deviation of age were 16.69 ± 0.78, among female students, there was a significant positive correlation between body mass index of perceived stress (p<0.05,r=0.27). BMI also had a significant positive correlation with  quality of life (satisfaction, negative emotions, relationship with science, progress, adventure, social cohesion and quality of life in general). There was no significant correlation between Body mass index of male students with perceived stress. Negative emotions had significant positive correlation (p<0.05,r=0.19) and the relationship with the teacher and social cohesion had significant negative correlation with body mass index (p<0.05). Perceived stress in boys and girls showed a significant different  and Mean of Perceived stress in girls was more than boys.(p<0.01).The adventurousness  among the components of quality of life had a significant difference between the groups in favor of girls (p<0.05). There was no significant difference in BMI. Most of the quality of life components had a significant negative relationship with perceived stress in boys and girls.
Conclusion: Stress management training programs and promotion of health-related quality of life can be effective in preventing obesity and overweight in girls and boys.