A small clinical trial supported by the NIH has found that eating during the nighttime—like many shift workers do—can increase glucose levels, while eating only during the daytime might prevent the higher glucose levels now linked with a nocturnal work life.
The findings, the study authors said, could lead to novel behavioral interventions aimed at improving the health of shift workers – grocery stockers, hotel workers, truck drivers, first responders, and others – who past studies show may be at an increased risk for diabetes, heart disease, and obesity.
The new study, which the researchers noted is the first to demonstrate the beneficial effect of this type of meal timing intervention in humans, appears online in the journal Science Advances. It was funded primarily by the NHLBI.
For the study, the researchers enrolled 19 healthy young participants (seven women and 12 men). After a preconditioning routine, the participants were randomly assigned to a 14-day controlled laboratory protocol involving simulated night work conditions with one of two meal schedules. One group ate during the nighttime to mimic a meal schedule typical among night workers, and one group ate during the daytime.
The researchers found that nighttime eating boosted glucose levels – a risk factor for diabetes – while restricting meals to the daytime prevented this effect. Specifically, average glucose levels for those who ate at night increased by 6.4% during the simulated night work, while those who ate during the daytime showed no significant increases.
“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,” said Marishka Brown, Ph.D., director of the NHLBI’s National Center on Sleep Disorders Research. “We look forward to additional studies that confirm the results and begin to untangle the biological underpinnings of these findings.”