Shift work is not only hard, it’s tough on the body. People whose shifts change from day to night and back again are far more likely to have high blood pressure, obesity, metabolic syndrome, cardiovascular disease, diabetes, and cancer.

Poor diet seems to be one of the culprits in a brew of factors leading to the greater risk of poor health among shift workers. And inflammation may be the root cause. The dietary inflammatory index (DII) measures the level of inflammation in the body. It appears to increase when a person works shifts — especially nights.

In an effort to maintain family life, shift workers often eat a meal with their families and then eat again while at work, leading to overeating.

Researchers at the University of South Carolina, Columbia ranked the diets of people who worked shift work, using data from the 2005 to 2010 National Health and Nutrition Examination Survey (NHANES), trying to find the differences among night/evening shift workers and rotating shift workers. They compared the inflammatory potential of their diets to those of day workers.

Shift workers' diets were more likely to raise DII and the risk of high blood pressure, obesity, and cardiovascular disease (CVD) because their diets were more inflammatory than those who worked the day shift.

People who worked the day shift had an average DII of (.86). Shift workers had a higher DII (1.07). Women’s DII scores were higher than men’s, and women who worked the evening or night shift had the highest DII (1.48) compared to the average of 1.17 among women who worked days.

Inflammation is a normal part of the body’s ability to heal itself. But smoking, high-fat high-calorie diets, and highly processed foods can stimulate an endless secretion of immune cells. This extra presence of these cells produces a chronic low-grade inflammation, which can set the stage for a host of chronic diseases.

Stress, fatigue, loss of sleep, and the disruption of the rhythms of family life all contribute to poor eating habits among shift workers.

Shift workers tend to snack more often. They may not have access to healthy foods while at work. In an effort to maintain family life, shift workers often eat a meal with their families and then eat again while at work, leading to overeating.

Increases in a person’s DII are believed to contribute to the health risks shift workers experience, but the importance of the DII to a person’s health is not yet proven. The health risks are likely connected to disruptions in the body's clock.

The study is published in the Journal of Occupational and Environmental Medicine.