What is leptin used for, the satiety hormone?
In recent years, several researchers have actually looked at studies on obesity. By the way, the problem of obesity is a major public health concern on a global scale. The origins of this condition are as diverse as they are complex. There are 3 main hormones in hunger control: leptin,ghrelinand insulin.
New recent studies have found that the hormone leptin plays akey role in metabolismandeating disorderslinked to weight gain problems. We dedicate here a special file on this scientific subject of great use.
What is leptin?
Among the many studies that attract the most attention of scientists on the problem of obesity, is the study ofdigestive hormones secretedby neurons: leptin. It is probably the most intriguing molecule of the lot. Also known as the “satiety hormone“, this protein is closely linked to theregulatory function of fat reservesin our body. It also regulates appetite andmodulates the feeling of hunger.
A hormone is a protein that acts as a messenger. Once released into the bloodstream, leptin acts on the hypothalamus to transmit its satiety message to specific receptors. In overweight people, the signals emitted by this message never seem to reach the brain, although they have high levels of leptin. This is calledleptin resistance.
This single discovery, supported by the explanations of Dr. Bruno Fève, endocrinologist at Saint-Antoine Hospital in Paris, has given a new direction to research in the field of endocrinology.
It is now known that leptin secretion evolves according to a circadian rhythm(1). Leptin levels are normally low in the morning (which makes you want to eat). It reaches a high threshold in the evening (which is the cause of the feeling of satiety). The lowest level is around noon. The highest leptin level is usually noticed after midnight.
How is leptin produced?
Leptin is produced by fatty tissue or adipose tissue. It exerts its actions through signaling brain cells toCurb Appetite and Eating, and thus increase energy expenditure. It is secreted into the blood stream in proportion to the energy mass stored in fat(2)tag. From there, leptin travels to the brain where it communicates exactlyhow much energy is available in the bodytag. In doing so, it regulates many essential physiological functions. These depend on proper caloric balance, reproduction, metabolism and bone formation.
Discovered in 1994, leptin is certainly best known today as a satiety, appetite regulating and weight hormonetag. But leptin is also involved in sending warning signals to neurons and other organs about the dangerous state of very low energy reserves in the body. It also plays a permissive role in the mechanism of puberty in young girls.
Leptin and obesity: what relationship?
A very recent scientific study (3)on appetite control and body weight regulation provides fairly precise answers on the question. It is led by scientists David Sunter, Donald O’Shea and Stephen R Bloom from the endocrine unit of the renowned Imperial College School of Medicine, Hammersmith Hospital, London, UK.
On a very simple scale, remember that obesity (4)results from a state of significant imbalance between excessive energy intake (through food) and insufficient caloric expenditure. This situation results in an effect of overweight, obesity, due to an excessive expansion of adipose tissue. At this point, leptin sends a signal to our hypothalamus. This provides information on the state of adipose tissue reserves, in order to enable usto limit our food intaketag. It is therefore a fairly specific hormone, useful for interpreting our eating behavior.
Why do we sometimes or always feel a craving for food? And why in other circumstances we feel sated.
For a high leptin level, our brain is instructed on our state of satiety. Leptin associates with certain sensors in the hypothalamus and stimulates therelease of appetite-suppressing chemical messagestag. People with leptin connection difficulties therefore haveeating disorders. As a result, they feed uncontrollably. Consequence: overweight, evenobesity can appear and settle permanently.
Leptin resistance
One would think that with the large amount of leptin they produce, obese people would find it easier to stop eating and thus lose weight. Unfortunately, as with insulin, there is a problem of leptin resistance.
If the amount of leptin stays high often enough, our leptin sensors become desensitized to the hormone over time (5)tag. We can then develop what is called “leptin resistance”. In this case, despite the excess fat mass, and the significant enough secretion of leptin to say stop storage, its message will have no influence:no loss of appetite and no increase in metabolism.
The person therefore eats constantly because the appetite does not weaken, increasing even more the amount of stored fat. But too much fat causes an even deeper disorder in the transmission of leptin. Having become resistant to leptin, the brain keepsactivating the feeling of hunger, which makes you want to eat more. This is the vicious circle of obesity!
Stephen Paul is the lead author and founder of My Health Sponsor. Holder of a diploma in health and well-being coaching with more than 200 articles in the field of health, he makes it a point of honor to offer advice based on reliable information, based on scientific research, and verified by health professionals.