The male employees who worked shifts during the study period, mainly doing aircraft or customer service, were less likely to eat at least one portion of vegetables per day than either day or in-flight shift workers. Meanwhile, women shift workers got 12.6 percent of their daily calories from saturated fat, compared to day workers’ 12.2 percent. Female shift workers also used more high-fat milk products than day workers.

Male shift workers consumed more calories from fat (33 percent) and saturated fat (12 percent) than the other two groups. Overall, shift workers also tended to gain more weight, the more they worked varying schedules. Night shift workers also slept less, which can lead to metabolic and cardiovascular problems, the study authors noted.