Have you ever been a bit crabby for seemingly no reason? How about snapping at someone unnecessarily, only to realize a few minutes later that you are seriously hungry? If so, then you have experienced something commonly referred to as “hangry”–being angry due to hunger.
Yes, this is a real phenomenon that has scientific reasoning behind it.
There are a few possible scientific reasons to explain the “hangry” sensation, each involving different processes that occur when the feeling of hunger begins to settle in. After eating, different proteins, fats, and carbohydrates, are broken down via the digestive system. The nutrients collected are sent as needed to the different organs and tissues within the body.
As the day goes on and hunger begins to settle in, the amount of nutrients and glucose within the body begins to decline. If the glucose levels fall to a low enough level, the brain reverts to ‘life is in danger’ mode. The brain, unlike other organs, depends on glucose exclusively in order to function effectively. (Other organs can rely on several different sources for nutrients.) When glucose levels are low, it becomes hard to think clearly, as the brain is having trouble functioning correctly.
Consequently, the brain may also have trouble realizing what the socially acceptable way of behaving is. For example, if glucose levels were normal, one might refrain from snapping at others when irritated, but with lower glucose levels, the brain does not have the energy needed to prevent the feelings of anger from manifesting.
Another cause for this feeling of being “hangry” is the glucose counter-regulatory response. When the glucose levels in the blood fall to a certain point, the brain sends signals to different organs in the body to produce and release certain hormones to increase the glucose amounts found in the blood stream.
One such hormone is adrenaline (also called epinephrine), which is secreted by the adrenal glands. Adrenaline is a stress hormone that is released in circumstances such as the “fight or flight” instinct during a frightening situation. During the “fight or flight” response one might easily act impulsively due to this increase in adrenaline. Similarly, when adrenaline levels have increased, the impulsive instinct to act on one’s anger comes to fruition due to low glucose levels and a lack of food.
A third reason involves genes. The product of a certain gene is neuropeptide Y, which is a natural chemical in the brain that is released upon hunger. In addition to controlling hunger feelings, neuropeptide Y also acts to regulate anger and aggression. An increase in feelings of hunger causes an increase in neuropeptide Y, causing higher levels of aggression.
So the next time you feel the seemingly unwarranted need to yell at the person next to you, maybe take a second, grab a bite to eat, and then reassess the situation on a full stomach and increased glucose levels.
From IFL Science