New research published in the journal "Obesity Reviews" suggests night shift workers have a higher risk of obesity or of being overweight.

The research includes an analysis of 28 observational studies that reported on an association between shift work and obesity, body mass index (BMI) or weight change.

Studies also had to meet a variety of criteria, including reliable assessment of shift work, conclusions with 95 percent confidence intervals and observational study designs.

Here’s what the researchers found:

  • Night shift work increases risk of obesity/overweight by 23 percent.
  • Night shift work increases risk of abdominal obesity, which is characterized by visceral fat accumulation in the abdomen and is commonly associated with abnormal metabolic profiles (like insulin resistance), by 35 percent.
  • Night shift workers between midnight and 5 a.m. showed a pooled estimate odds ratio of 1:32, meaning the odds of obesity/overweight is 1.32 higher for night shift workers compared to non-night shift workers.
  • Permanent night shift work showed a higher risk of obesity/overweight than rotating shifts, possibly due to daytime environmental hours interrupting proper sleep.
  • Highest risks were among 10-hour permanent night shifts or 12-hour rotating shifts compared with other night shift work.

Why are night workers at risk?

Read more here.