en Occupational Health Original Article <div style="text-align: justify;"><span style="font-family:times new roman;"><strong>Background:</strong> Nowadays, shift work is a common work schedule. Shift work has been hypothesized as a risk factor for obesity. So, identifying the effective factors on obesity is of great importance. In the present research, we are going to study the effects of shift work on obesity among military personnel in 2016.<br> <strong>Materials and Methods: </strong>This <a name="OLE_LINK123">descriptive </a>study was carried out on 80 man military at southern Iran in June and July 2016. Respondents were divided into two groups based on their working schedule (40 shift work and 40 day work personnel). These two groups were matched in terms of type work. In this study, the participants were selected through simple random sampling. In this research, we controlled the effect of age and work experience on obesity. Finally, data analysis was performed with SPSS software.<br> <strong>Results:</strong> Total people who participated in this study were 80. <a name="OLE_LINK15">The findings revealed that mean body weight and body mass index (BMI) in shift workers were more than day workers.</a> The <a name="OLE_LINK12">results also showed that 79.6% of subjects had BMI > 25 in shift work individuals. Furthermore, 83.9% of subjects had BMI < 25 in day work individuals</a>. Finally, Pearson correlation test showed a significant correlation between BMI <a name="OLE_LINK19">(r = 0.69) </a>and weight (r = 0.67) with years on shift work, in a way that with increasing duration of shift work, BMI and weight increased.<br> <strong>Conclusions:</strong> The duration of shift work was positively associated with the prevalence of obesity in military personnel and shall be taken to intervention actions in shift works.</span></div> Obesity,Body Mass Index,Shift Work,Military Personnel, 178 183 http://johe.rums.ac.ir/browse.php?a_code=A-10-128-7&slc_lang=en&sid=1 A Ghanbary Sartang aioobghanbary@ymail.com 22400319475328460010352 22400319475328460010352 Yes School of Health, Isfahan University of Medical Sciences, Isfahan, Iran. Isfahan University of Medical Sciences M Ashnagar m.ashena@yahoo.com 22400319475328460010353 22400319475328460010353 No Dept. of Industrial Psychology, Islamic Azad University of Marvdasht, Shiraz, Iran. Islamic Azad University of Marvdash M Abedi habibi.hlth@mui.ac.ir 22400319475328460010354 22400319475328460010354 No Safety and Environment (HSE), Center Tehran Azad University of Medical Sciences, Tehran, Iran Center Tehran Azad University of Medical Sciences E Habibi 22400319475328460010355 22400319475328460010355 No Dept. of Occupational Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran. Isfahan University of Medical Sciences