The interaction of hunger and satiety happens in our body several times a day. The control center is located in our brain: in the hypothalamus. Here are the signals the body sends when you feel hungry or full. But not only exercise determines appetite. External stimuli, such as a particular smell, the appearance of a food, or a particular taste, also affect our feelings of hunger. Physiological and emotional (hedonic) signals condition each other and are closely related.
How does the feeling of satiety occur?
Hunger is the body’s alarm signal. Organs, especially the brain, need energy to function optimally. This is why hunger ends up turning into an irresistible need. Consequences can include restlessness and aggression. That’s why we try to satisfy our hunger as quickly as possible.
Once in the stomach, food stretches the stomach wall. This is sent to the brain by so-called mechanoreceptors. But the distention of the stomach in itself does not cause a feeling of satiety. Additionally, so-called chemoreceptors in the intestines and liver determine the amount of nutrients that have been absorbed. In this case, the secretion of various hormones important for the energy balance of the body occurs, the pancreas causes an increase in blood sugar levels. Gut microorganisms also send signals. It is only when the mechano- and chemoreceptors respond and the hypothalamus receives a message about the correct level of hormones that we begin to feel full. This is when the body releases the happiness hormone, serotonin, among others, signaling, “I’m full, I’m satisfied.”
According to research, it takes between 300 and 400 cubic centimeters to fill the organ with a volume of 300 to 400 cubic centimeters – about a small to medium serving of pasta – to properly stretch the stomach. Fluids can also stretch the stomach, but they usually pass quickly through the intestines.
Hungry or satiated? Different hormones involved
According to science, many hormones affect feelings of hunger and fullness. However, many interactions have not yet been studied. Overview of the main satiety hormones:
Leptin constantly gives the body feedback on the energy state. The hormone is associated with body fat. When leptin levels drop, we are hungry. When we eat food, its level increases again and the hormone contributes to the feeling of satiety.
Ghrelin is a leptin antagonist and is also called the “hunger hormone”. When the stomach is empty and the body needs energy, ghrelin levels rise. If eaten, its value will drop again.
When fatty acids and amino acids are absorbed from the intestines, cholecystokinin is produced. This hormone is also responsible for the feeling of satiety.
The digestive hormone GLP-1 also has a satiating effect, it is released during the absorption of glucose and fatty acids.
In addition, due to the increase in glucose levels, the hormones amylin and insulin are produced, which also contribute to the feeling of satiety.
How long does it take to be full?
It is only after about 20 minutes that a conscious feeling of satiety usually occurs. In this case, different nutritional composition factors play a role:
Satiety depends on hormones, which are also released in varying degrees with different food composition. This is the case, for example, with sweet foods such as chocolate: they contain a high dose of glucose, from which the body quickly draws energy. Thus, sweet signals the body for a short-term burst of energy. But, unfortunately, it is also high in calories and, as a rule, contains little or no fiber and other valuable nutrients. Sweets also cause blood sugar levels to rise very quickly and fall again after insulin is released, and low blood sugar levels cause hunger.
But psychological aspects also play a role in the feeling of satiety. Eating at a particularly good restaurant or hanging out with people you know affects our feelings of hunger and fullness.
Lack of satiety – what are the reasons?
Our body is programmed to want food that is readily available. However, in an age where food and snacks are constantly at hand, this becomes a problem. Additionally, we often eat to reward ourselves, relax, or cope with stress. Overview of reasons:
Chronic stress and lack of sleep increase cortisol levels, the reward system in the brain stimulates the appetite for sweets and fats. Result: patients take crisps or chocolate to relax. Emotions guide our behavior, and the perception of physical sensations of satiety fades into the background, we no longer perceive them as well. Additionally, a chronically stressed brain consumes less energy, receives less food, and leaves more for the body. Thus, fatty deposits develop because food is less digestible.
The lack of a natural feeling of satiety can also have psychological causes, such as those caused by trauma. This can happen with obesity, as well as with anorexia (anorexia) or bulimia (overeating addiction).
Taste can also be associated with emotions. Sweets are often invented in childhood as a delicacy. Babies are also very sensitive to sweet tastes, which can be associated with nurturing and emotional warmth, and if we feel the need, we seek out something that tastes like inner warmth – chocolate, for example. Because the energy density is high, we can also eat a lot without triggering the satiety system.
Fast food: French fries or burgers have a high energy density in a relatively small amount. The stomach needs more because it is not stretched enough yet. Then the food is consumed quickly, so the feeling of fullness cannot arise.
The hormone leptin and fat cells are directly related to each other. The more fat cells there are in the body, the higher the level of leptin. Thus, in case of overweight, a so-called leptin resistance can develop. That is to say, the feeling of satiety is no longer present in those who suffer from this disease. Belly fat, in particular, plays an important role here.
Food can also disrupt the feeling of satiety: if you suddenly reduce your calorie intake drastically, the body will react with hunger. The reason for this is the high production of the hormone ghrelin. If the diet is canceled now, irritation will occur in the body, such as continuing the diet and then switching to a normal diet.
Medications such as antidepressants, antiepileptics, and antipsychotics that directly affect brain metabolism can cause a lack of satiety. Diabetes medications, blood pressure medications, and cortisone can also have this effect.
Food cravings often occur when blood sugar levels drop rapidly and dramatically. So, eating a meal with a lot of sugar or simple carbs can make the feeling of fullness not last long.
Eat slowly and take breaks
Mindful eating is an important step towards healthy eating and, therefore, a feeling of satiety. It is important to eat mindfully. Already in the mouth, one can consciously influence satiety. Conscious and prolonged chewing of food contributes to better satiety. Plus, due to their high nutritional value, unprocessed and natural foods keep you feeling full longer than fast food or processed foods. The consistency of the food also plays an important role: Foods that resist bites keep you feeling full longer than soup without a side dish.
See also: The therapist busted the myths about depression.
The material is for informational purposes only. Before using the site’s recommendations and advice, a full-time consultation with your doctor is necessary.
