National Institutes of Health-funded research has revealed that eating throughout the night, like many shift workers do, can raise blood glucose levels, but merely eating during the daytime may prevent the higher glucose levels typically associated with a shift work lifestyle. Findings from the study could lead to novel behavioral interventions aimed at improving the health of shift workers, who previous studies have shown may be at an increased risk for diabetes, heart disease, and obesity. These workers include grocery stockers, hotel workers, truck drivers, and first responders.
According to the study’s authors, this is the first time this type of meal timing intervention has been shown to have a positive impact on human health. The findings are published in the journal Science Advances. National Institutes of Health (NIH) financed the majority of the research.
Director of the NHLBI’s National Center on Sleep Disorders Research, Dr. Marishka Brown, said, “This is a rigorous and highly controlled laboratory study that demonstrates a potential intervention for the adverse metabolic effects associated with shift work, which is a known public health concern,” Additional research that validate the findings and begin to unravel the molecular foundations of these discoveries are eagerly anticipated.”
Researchers recruited a healthy young population for their study, including 19 individuals (seven women and 12 men). As part of the experiment, the volunteers underwent a preconditioning procedure before being randomly allocated to one of two meal patterns for the 14-day period that followed. For the sake of simulating the eating habits of shift workers, one group ate at night while the other ate during the day.
After that, they looked at how various meal regimens affected their circadian cycles internally. In addition to regulating your sleep-wake cycle, this biological process also controls the 24-hour cycle of practically all bodily functions, including metabolism.
Researchers discovered that eating at night increased blood glucose levels, which is a risk factor for diabetes, although eating only during the day did not. People who ate during the daytime exhibited no significant increase in glucose levels during the simulated night shift, while those who ate at night saw an increase of 6.4 percent.
This is the first study to show that meal timing can be used to counteract the negative effects of impaired glucose tolerance and disrupted circadian rhythms resulting from simulated night work,” study leader Frank A.J.L. Scheer, Phd, of Harvard Medical School and Brigham & Women’s Hospital in Boston, said in a statement.
The mechanisms behind the reported impacts, according to the researchers, are complicated. Circadian misalignment is thought to be responsible for the glycemic effects of nighttime meals on simulated night work. Misalignment of the central circadian “clock” (placed in the hypothalamus of the brain) with behavioral sleep/wake, light/dark and fasting/eating cycles can affect peripheral “clocks” throughout the body. This is the cause of the problem. Mistiming of the central circadian clock in relation to fasting/eating cycles has been found to play a significant effect in raising glucose levels. A better synchronization of these central and peripheral “clocks.” may explain the positive effects of daytime feeding on glucose levels during simulated night work.
According to lead researcher Sarah L. Chellappa, M.D., Ph.D. of the University of Cologne’s Department of Nuclear Medicine, “This study reinforces the notion that when you eat matters for determining health outcomes such as blood sugar levels, which are relevant for night workers as they typically eat at night while on shift,” she said. Before joining Brigham & Women’s Medical Chronobiology Program, Chellappa worked with Scheer.
In order to implement these findings into practical and effective meal-timing interventions, experts recommend conducting additional research with real-life shift employees in their regular workplace.
