Study Finds Shift Workers More Likely to Have Weight & Sleep Issues

Various factors can increase workers’ likelihood of getting hurt on the job, such as being overweight, being tired and doing shift work. A recent study ties these factors together, showing that shift workers are more likely to be overweight and have sleep issues.

The study from the University of Wisconsin School of Medicine and Public Health looked at shift workers—defined as those who work at night, rotating or other alternate shifts—and examined occupational, sleep behavior and metabolic health data from the 1,593 participants in the Survey of the Health of Wisconsin (SHOW).

Researchers found that shift workers were more likely to:

  • Be overweight than traditional-schedule workers (83% v. 71% with a body mass index of 25 or more); and
  • Report more sleep problems, such as insomnia (24% v. 16%), insufficient sleep (53% v. 43%) and sleepiness (32% v. 24%).

Dr. Marjory Givens, lead author of the study and associate scientist at the University of Wisconsin School of Medicine and Public Health, said, “We found that shift workers are prone to sleep problems and poor cardiometabolic health including obesity and diabetes, and that the chances of being overweight were even greater for shift workers who did not get enough sleep. This suggests that the adverse metabolic implications of working shifts could be alleviated by getting enough sleep.”

Givens and colleagues found that even though sleep problems didn’t fully explain the association between shift work and being overweight or diabetic, these associations appeared to be stronger among shift workers who weren’t able to get sufficient sleep (less than seven hours per day).

In addition, “if you work at night and sleep through the day, you’re not going to have the same options for undisturbed sleep, access to healthy foods or venues for physical activity that people who work traditional hours have,” said Dr. Javier Nieto, senior author and principal investigator of the study, and chair of the UW Department of Population Health Sciences.

“Most gyms, grocery stores, restaurants and other venues have schedules that complement the 9-5 work schedule,” he noted.

“Observational studies can’t prove causality, but there is enough evidence – from our study and many others like it – to suggest that shift work may negatively affect health,” said Nieto. “If businesses are interested in the health of their workers, finding cost-effective ways for employees to be healthier while continuing to work nontraditional hours would be mutually beneficial for workers and employers.

For more information on the impact of shift work, obesity and sleep disorders on workers and workplace safety, see: