The nerves in the stomach act as a circadian clock - a biochemical mechanism that oscillates with a period of 24 hours - limiting food intake to specific times of the day, according to a new study.
During the study, researchers at the University of Adelaide investigated how the nerves in the stomach respond to stretch, which occurs as a consequence of food intake, at three-hourly intervals across one day, according to a press release.
"These nerves are responsible for letting the brain know how much food we have eaten and when to stop eating," Dr. Kentish, lead author of the paper, said in a statement.
Researchers found that the nerves in the gut are at their least sensitive at time periods associated with being awake, like the day time. This means more food can be consumed before people feel full at times of high activity, or when more energy is required.
The circadian clock is also coordinated with the day-night cycle. Kentish said altering this cycle could limit food intake.
"With a change in the day-night cycle to a period associated with sleeping, the nerves in the stomach become more sensitive to stretch, signaling fullness to the brain quicker and thus limiting food intake," Kentish said. "This variation repeats every 24 hours in a circadian manner, with the nerves acting as a clock to coordinate food intake with energy requirements."
So far researchers have only made this discovery in laboratory studies, not in humans. But Kentish said he believes the same variations in nerve responses exist in human stomachs, "with gut nerves being less sensitive to fullness during the day and more sensitive at night."
In a prepared statement, study leader Associate Professor Amanda Page said this research could lead to further discoveries about how changes in people's circadian clocks affect their eating habits.
"We know that shift workers, for example, are more prone to disruptions in sleep and eating behavior, leading to obesity and other health problems," she said.
The study could lead to new information about how the gut signals to our brains about when we're full, and when to keep eating. According to Page, researchers are now conducting further research to see what kind of impact such changes to the circadian rhythm will have on eating behavior, and how the nerves in the stomach react to those changes.
