Help the development of the site, sharing the article with friends!
Why some people almost do not feel hungry at all, while others constantly have a huge appetite? This is due to a complicated mechanism of feeling hungry and full of satiety, largely controlled by hormones.
The center of hunger and satietyis the hypothalamus - the part of the brain that coordinates many vital functions. There are many ways to get signals that increase or decrease the appetite. The first type of information transmitted to the brain ismotor signals , related to the contraction and expansion of the stomach walls. When we do not eat anything for a long time, the stomach walls contract, and the so-called Mechanoreceptors tell the brain that we are hungry. After the meal, the stomach fills up and sends a signal to the brain to finish eating (it takes up to several minutes, so remember to get up from the table slightly unsatisfied).
Another type of signals sent to the hypothalamus are the so-calledmetabolic signals . After digesting a meal, the blood levels of compounds that are products of carbohydrate, fat and protein metabolism increase. The high level of these ingredients (including glucose, free fatty acids or amino acids) gives a signal of satiety, which lasts until the body uses them.
How do hormones control our appetite?
The most complex mechanism of appetite control is thehumoral mechanism , which is related to the secretion ofhormonesdirectly or indirectly to the brain and causing the appropriate responses. The most important of them are:
- CHOLECYSTOKININ - a hormone secreted by the walls of the small intestine under the influence of food, causes the expansion of the stomach walls and the feeling of fullness;
- INSULIN - is secreted by the pancreas, increases blood glucose levels and activates the production of LEPTIN, which increases the feeling of satiety and inhibits the production of the neuropeptide responsible for the feeling of hunger;
- SEROTONIN - the happiness hormone - suppresses the appetite mainly for carbohydrates.
The complexity and multitude of mechanisms of feeling hungry and full makes it impossible to determine which one is decisive. The matter is additionally complicated by the fact that the mode of operation of individual mechanisms depends on the genetic predisposition or the physiological state of the organism. For example, produced leptinin adipose tissue should suppress the appetite to a much greater extent in obese people than in those of normal weight. It is known, however, that overweight people develop resistance to this hormone, which makes it difficult to refuse food. Traditions, cultural and eating habits learned from childhood are also important. Until we understand all these issues and treat them as a whole, we will not be able to fight the scourge of obesity.
How to fight hunger he althily?
We eat more in winter
The mechanisms of hunger and satiety are complemented by thermal signals sent by thermoreceptors located e.g. on the skin. They are related to the need to maintain a constant body temperature, regardless of the ambient temperature. It is the thermal signals that are responsible for the increase in appetite in winter and for its decrease on hot days or during fever.
"Zdrowie" monthly
See the gallery of 9 photos