You slept enough last night, you’re not particularly bored (although), and yet… Impossible to repress one or more “yawns”, even in the middle of an open space. Wouldn’t it soon be time to eat? Because little is known, but hunger can also make you want to yawn. And no, it’s not just an excuse. Explanation from our medical director, Dr. Gérald Kierzek.
A reflex much more complex than it seems
Yawning is an automatic reflex which manifests itself by a deep inspiration, a maximum opening of the mouth, followed by a contraction then a relaxation of many muscles of the face, neck and thorax. For a long time, it was believed that it essentially served to oxygenate the brain. A theory that is now largely abandoned.
“Oxygen levels do not increase after yawning,”
recalls Dr. Gérald Kierzek. Moreover, this behavior also exists in fetuses or in certain animals which yawn in a liquid environment, proof that it is not a simple need for fresh air.
Hunger and yawning: a story of energy and vigilance
So why do we yawn when we’re hungry? The answer lies in our energy level. According to specialists, yawning plays a key role in regulating alertness, particularly during transitions between different physiological states.
“We often yawn during transitions between wakefulness and sleep, but also between satiety and hunger.“, explains the doctor. When the body lacks fuel, brain performance decreases slightly, as does the level of attention.
“Yawning would then act as a stimulation mechanism, a sort of alert signal sent to the brain to stay awake and focused despite the drop in energy..
In other words, yawning when you are hungry would be a way for the body to temporarily compensate for this deficit, while waiting for food intake.
Other situations conducive to yawning
Hunger is obviously not the only culprit. We also yawn frequently when we wake up, when tired, after a heavy meal, during moments of boredom or even in a stressful situation. All these contexts have one thing in common: they correspond to variations in the waking state.
Although the exact role of yawning is not yet fully elucidated, researchers agree on several additional hypotheses. It would participate in the regulation of vigilance, the adjustment of brain temperature and even a form of social communication, particularly when a yawn becomes contagious.
But if your eyelids get heavy just before lunchtime, and your jaw inevitably drops, there’s no need to feel guilty. This yawn is neither a sign of laziness nor a lack of sleep, but simply one of the many signals sent by your body to remind you that it is time to eat. And you can remind those around you of that… between two yawns.