International Journal of Preventive Medicine (Int J Prev Med)2008-7802002016101717401740ENDepartment of Public Health, School of Health, Urmia University of Medical Sciences, Urmia & Department of Health Education and Health Promotion, Isfahan University of Medical Sciences, IsfahanDepartment of Health Education and Health Promotion,Isfahan University of Medical Sciences, IsfahanDepartment of Epidemiology, School of Medicine, Urmia University of Medical Sciences, Urmia20161017<p><strong>Background:</strong> Obesity is a major problem in both developed and underdeveloped countries. The aim of this study is to investigate the effects of a physical education program (PEP) on promoting<br />health belief model (HBM) scores, increasing physical activity (PA), and reducing obesity among Iranian high school students.</p><p><strong>Methods:</strong> This quasi‑experimental study was accomplished at four high schools that were randomly divided into two groups of experiment (forty) and control (forty) male students in junior<br />high schools in Urmia, Iran. Students in the experimental group received a PEP during 6 months. The essential parameters were used for evaluating the effects of educational program on HBM,<br />PA, and body mass index (BMI) of students.</p><p><strong>Results:</strong> After the intervention of 3 and 6 months, the experimental group showed a significant difference on the results of HBM constructs. According to the result of repeated‑measures ANOVA, there is a significant difference between the experimental and control groups about<br />the components of PA constructs. Analysis of covariance showed that although BMI reduced in 6 months after intervention, there was no significant difference in BMI.</p><p><strong>Conclusions:</strong> Results of the study revealed that implementation of PEP was effective on increasing the score of the components of HBM and PA of students.</p><p><strong>Keywords:</strong> Health belief model, obesity, physical activity, physical education program</p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1740http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1740/2030