Switching from the day change to working evenings or nights may affect your waistline, according to a new study from Australia, part of a growing body of research indicating working at night can lead to weight gain.
Nurses & midwives in the study who switched from working mostly during daylight hours to working odd hours in the evening & night saw an increase in their body mass indexes over a two-year duration. In contrast, those who switched from working at nighttime to working in the day had decreases in their BMIs.
The findings held even after the finder took into account factors that could influence a person’s weight, including diet quality, physical activity, smoking & alcohol consumption.
Isabella Zhao, of the College of Queensland School of Nursing & Midwifery in Brisbane, & colleagues surveyed more than 2,000 nurses & midwives in Australia & contacted them again two years later.
Participants were asked to report their normal work hours, as well as their height & weight, which researchers used to calculate their BMIs. (A person with a BMI between 25 & 30 is considered overweight & a person with a BMI of 30 or higher is considered obese.)
Participants who switch as of working evenings & nights to working during the day saw their BMIs decrease by 3 units on average.
In contrast, participants who continued to work the night shift, or who altered from working the day shift to working the night shift, saw a growth in their BMI of about 0.5 units, the seeker said.
Night shift workers may gain weight because their biological clocks are disrupted, Zhao said. Studies have exposed that people who work at night produce less leptin, a hormone that signals the body to end eating, & more cortisol, which has been linked to obesity, Zhao said. However, more do research on this matter is needed, Zhao said.
Some factors that might have affected the results were not included in the perusal, such as whether participants suffered from depression, the researchers said. In augmentation, the researchers may not be aware at what point during the study the participants changed shifts.