Rethinking night shift eating: A path to healthier lives

Over the years, multiple studies have revealed the health hazards faced by night shift workers. A latest Australian study has found that night shift workers who eat full meals or snacks overnight have worse glucose tolerance, increasing their risk of chronic health issues like diabetes and heart disease. Conducted over six days with 55 participants, the study showed that fasting at night helps maintain balanced blood sugar levels, while eating overnight disrupts insulin sensitivity.
Led by researchers from the University of South Australia (UniSA), University of Adelaide, and South Australian Health and Medical Research Institute (SAHMRI), the study involved a six-day trial with 55 adults in the healthy BMI range, who don’t usually work night shifts. Participants stayed at the University of South Australia’s Behaviour-Brain-Body Sleep Research Centre and were divided into three groups: those who fasted at night, those who had snacks, and those who ate full meals. All participants stayed awake for four nights and slept during the day, with a recovery day on day five to re-establish normal sleeping and eating cycles, and blood glucose testing on day six.
Leonie Heilbronn, PhD, from SAHMRI and the University of Adelaide, said results showed participants who ate meals or snacks during the night shift had significantly worse glucose tolerance compared to those who fasted. “We found that blood glucose skyrocketed for those who ate full meals at night and those who snacked, while the people who fasted at night showed an increase in insulin secretion which kept blood sugar levels balanced,” Heilbronn said in a news release. “We know shift workers are more likely to have diabetes. They’re more likely to have heart disease, and they’re more likely to be overweight. Our research suggests that meal timing could be a major contributor to those issues.”
Insulin sensitivity was disrupted among all participants, regardless of their eating habits, adding to the body of evidence that night shifts cause circadian misalignment and impair glucose metabolism. “When you eat a meal, your body secretes insulin, and that insulin helps your muscles and other tissues to take up glucose. If you become resistant to insulin, then you can’t take up that glucose as effectively into your muscles, and if it continues, that potentially puts you at risk of diabetes,” she said in a release.
According to lead investigator UniSA professor Siobhan Banks, PhD, not eating large meals while working night shift and instead eating primarily during the day could be a straightforward intervention to manage health outcomes for many workers. “This could be easier for people to follow than other, more complex diets,” Banks said in a release. Researchers say future trials will investigate whether eating only protein snacks on night shift is a potential solution to satiating hunger without predisposing workers to negative health consequences.
Despite the scientific evidence, night shifts are prevalent in many sectors across various industries. As night shift workers have experienced, it is nearly impossible to work on an empty stomach. So, the only way out is to create awareness among the target group about the urgent need to eat healthy to minimise the ill effects of night shift and thereby strike a balance between work requirements and health.