How the hormone leptin influences our body weight

How leptin works in the body

Leptin is a metabolic hormone, also known as proteohormone, and is produced in white adipose tissue (abdominal fat). The active hormone synthesized in the human body consists of 146 amino acids. As an adipokine (protein), the hormone is largely produced in the fat cells and subsequently released. If the fat cells release leptin, it is transported to the brain via the blood. If there is a lot of leptin in the blood, the brain signals to the body that there is enough energy in the form of fat. If leptin is active in the body, energy-consuming processes are started. These include, for example, an increase in metabolism, higher activity of the sympathetic nervous system and the thyroid gland.strong>of the thyroid as well as regeneration and building up of tissue such as muscles or skin. ^[1][2]

Leptin as the most important settling hormone

The more abdominal fat a person has, the more leptin can be produced. In overweight people, greater amounts of leptin are therefore produced. However, due to increased levels in the bloodstream, the brain in particular develops a resistance to the hormone over time. This is known as leptin resistance. But what does this mean? Much more leptin is required in the brain for the transmission of the satiety signal, which in turn has hardly any effect in the case of resistance. The result is that overweight people actually have energy stored in abundance, but the feeling of hunger is no longer appropriately inhibited by the hormone. The basal metabolic rate drops and even more fat is stored through food intake – a „vicious circle“ is created. The consequences are similar to a lack of body fat, although exactly the opposite happens. Symptoms occur, such as an increased feeling of hunger, fatigue or cold chills.strong>cold hands and feet – up to a metabolic syndrome.

What influence does leptin have on reproduction?

Only with the „consent“ of the hormone leptin is pregnancy even possible. Because without it, the woman's egg production fails. ^[3]

If a woman cannot muster the necessary energy for a pregnancy, this serves as a protective mechanism for mother and child. Although there is enough body fat, leptin resistance leads to the same symptoms as a leptin deficiency: The body conserves energy and prevents a possible pregnancy.

The hormone leptin and our immune system

A leptin deficiency is associated with an increased risk of infection in children and adults. ^[4] Although the brain assumes a deficiency, increased leptin levels occur in the bloodstream due to leptin resistance. This leads to a permanent inflammatory activation of the immune system with consequences for the functioning energy distribution. A chronic, low-grade inflammation develops, which can end in modern disease patterns. ^[5]

Why does leptin resistance make you tired

One function of leptin, for example, is to report to the brain after getting up: „There is enough energy, you can get up fresh and alert!“ Leptin activates the thyroid glands and all „expensive“ organs such as heart or muscles and we can move efficiently. From an evolutionary perspective, this makes perfect sense. Because fresh food, as we know it today, did not exist among our ancestors. They first had to go in search of food. Therefore, after getting up, the digestion and production of amylase, a digestive enzyme, is inhibited because it is not necessary for the search for food. Eating directly after getting up therefore appears not particularly useful from an evolutionary point of view.

Food as medicine

The food tamarind (Säure HCA) can reduce the leptin concentration in the blood, LDL values (cholesterol) and triglyceride values have been shown to significantly reduce. At the same time, parameters such as HDL (cholesterol) and the smooth muscle hormone serotonin increase. ^[6]