Health Risks From Working Nights My Be Reduced By Daytime Meals. A tiny clinical trial funded by the National Institutes of Health discovered that eating late at night, as many shift workers do, can raise glucose levels, whereas eating just during the day can prevent the higher glucose levels now associated with nocturnal work. The findings could lead to novel behavioral therapies aimed at improving the health of shift workers, such as grocery stockers, hotel workers, truck drivers, first responders, and others, who have been linked to an elevated risk of diabetes, heart disease, and obesity in previous research.
The new study, which the researchers claim is the first to show that this form of meal timing intervention is advantageous in humans, is published online in the journal Science Advances. The National Heart, Lung, and Blood Institute (NHLBI), which is part of the National Institutes of Health (NIH), was the primary funder.
“This is a thorough and well-controlled laboratory trial that reveals a potential intervention for the negative metabolic effects of shift work, which is a well-known public health concern,” said Marishka Brown, Ph.D., director of the NHLBI’s National Center for Sleep Disorders Research. “We eagerly await more research to corroborate the findings and begin to unravel the scientific foundations of these findings.”
The researchers recruited 19 healthy young people for the study (seven women and 12 men). The participants were randomly allocated to a 14-day controlled laboratory regimen incorporating simulated night work conditions with one of two meal plans after a preconditioning process. One group ate at night to simulate the meal routine of night workers, whereas the other group ate during the day.
After that, the researchers looked at how various meal regimens affected their internal circadian cycles. That’s the internal mechanism that controls not only your sleep-wake cycle, but also the 24-hour cycle of nearly all of your biological functions, including metabolism.
The researchers discovered that eating late at night increased glucose levels, which is a risk factor for diabetes, whereas eating just during the daytime reduced this impact. Specifically, during the simulated night work, average glucose levels for those who ate at night climbed by 6.4 percent, while those who ate during the daytime exhibited no significant increases.
“This is the first study in humans to show the use of meal timing as a countermeasure against the combined negative effects of impaired glucose tolerance and disrupted circadian rhythm alignment caused by simulated night work,” said study leader Frank A.J.L. Scheer, Ph.D., professor of medicine at Harvard Medical School and director of the Medical Chronobiology Program at Brigham & Women’s Hospital in Boston.
The mechanisms behind the reported impacts, according to the researchers, are complicated. They believe that circadian misalignment is to blame for the impact of evening meals on glucose levels during simulated night work. The misalignment of the central circadian “clock” (placed in the hypothalamus of the brain) with behavioral sleep/wake, light/dark, and fasting/eating cycles, which can influence peripheral “clocks” throughout the body, correlates to this. Mistiming of the central circadian clock with the fasting/eating cycles, according to the current study, is a crucial factor in raising glucose levels. The findings also suggest that the favorable benefits of daytime feeding on glucose levels during simulated night labor could be attributed to a better synchronization of these central and peripheral “clocks.”
“This study supports the idea that when you eat matters for determining health outcomes like blood sugar levels,” said study co-leader Sarah L. Chellappa, M.D., Ph.D., a researcher in the nuclear medicine department at the University of Cologne, Germany. Chellappa previously worked in the Brigham and Women’s Medical Chronobiology Program with Scheer.
More research, including with real-life shift employees in their regular work setting, is needed to translate these findings into practical and successful meal scheduling interventions, according to the researchers.