A study published in The Journal of Neuroscience shows that nerves in the stomach may act as a circadian clock, limiting food intake to specific times of the day. The discovery could lead to new information about how the gut signals to our brains about when we’re full, and when to keep eating.
In the University of Adelaide’s Nerve-Gut Research Laboratory, the researchers 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.
“What we’ve found is that the nerves in the gut are at their least sensitive at time periods associated with being awake,” said Stephen Kentish, lead author. “This means more food can be consumed before we feel full at times of high activity, when more energy is required. However, 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. This variation repeats every 24 hrs in a circadian manner, with the nerves acting as a clock to coordinate food intake with energy requirements.”
So far this discovery has been made in laboratory studies, not in humans. “Our theory is that the same variations in nerve responses exist in human stomachs, with the gut nerves being less sensitive to fullness during the day and more sensitive at night,” said Kentish.