You know the drill: You get home from work and the gym, set your stuff down, and the minute your hands are free, your stomach starts to rumble—as if on cue. Well, turns out it's not a coincidence. Scientists now have an explanation for why our appetites seem to work like clockwork. In their study of the mechanics behind hunger pangs, researchers from Australia's University of Adelaide have discovered that the nerves in the stomach act as a circadian clock, limiting hunger to specific times of the day.
The study looked at how the nerves in the stomach respond to the stretching that occurs when you eat. These nerves are largely responsible for telling your brain how much food you've eaten, and when it’s time to stop.
“What we’ve found is that the nerves in the gut are at their least sensitive at periods associated with being awake. This means more food can be consumed before we feel full at times of high activity, when more energy is required," explains lead study author Stephen Kentish, Ph.D.
Translation: The nerves in your gut are less sensitive (i.e., it takes longer to feel full) during the day because your body needs food to fuel your daily activities. During the evening hours, your stomach becomes more sensitive (i.e., you'll feel fuller faster), as nighttime is associated with sleeping and therefore requires less activity or energy. According to the study, this cycle repeats every 24 hours in a circadian manner with stomach nerves acting as a clock to coordinate food intake with energy requirements.
Bottom line: If you’re looking to lose weight, listen to your body—it knows what you need, and when.