Association between Shift Working and Markers of Obesity: A Cross Sectional Study on Taxi Drivers in Yazd, Iran

Background: Obesity is one of the most important health problems, so it is very important to identify its causes. Shift work is one of the factors that causes people to become obese. The aim of this study was to examine the relationship between shift work and obesity in taxi drivers. Methods: In this cross sectional study conducted in 2016, 120 male taxi drivers from Yazd were studied for demographic characteristics and some anthropometric indices. To describe the data, descriptive statistics were used; to compare the prevalence of overweight, general and abdominal obesity, chi-square test was used and to compare quantitative variables, independent t-test and Mann-Whitney test were used. Results: The results showed that the mean weight, waist circumference, body mass index and waist to hip ratio (WHR) were significantly higher in shift workers (P < 0.05). In this study, the prevalence of overweight in shift and day workers was 41.4 and 46% (P = 0.61), general obesity was 34.3 and 20% (P = 0.08), and abdominal obesity was 82.9 and 82% (P = 0.90), respectively. Spearman correlation coefficient showed a positive and significant correlation between age and WHR as well as work experience and WHR in shift workers (r = 0.34 and r = 0.31, respectively). Also, a positive and significant correlation was found between age and WHR in day workers (r = 0.35). Conclusions: The results of this study showed that shift work in taxi drivers is associated with an increased probability of overweight, general and abdominal obesity.