Ghrelin: The Hunger Hormone

Ghrelin is a hormone produced by the stomach that plays a crucial role in regulating hunger and appetite. This hormone is known as the "hunger hormone" because it signals the brain to increase food intake. In this essay, we will explore the functions and effects of ghrelin on the body.

Ghrelin is released by the stomach when it is empty and stimulates appetite by acting on the hypothalamus in the brain. It increases the release of neuropeptide Y, a neurotransmitter that stimulates appetite and reduces energy expenditure. Ghrelin also decreases the release of leptin, a hormone that signals the body to stop eating when it is full. This leads to an increase in food intake and a decrease in metabolic rate.

Ghrelin plays an important role in weight regulation. Studies have shown that levels of ghrelin increase before meals and decrease after meals. This suggests that ghrelin may be involved in meal initiation and termination. Individuals with obesity have been found to have lower levels of ghrelin compared to individuals with normal weight. This suggests that a decreased response to ghrelin may be a contributing factor to the development of obesity.

Ghrelin has also been found to stimulate the secretion of growth hormone from the pituitary gland. Growth hormone plays a role in regulating body composition, bone growth, and metabolism. Studies have shown that ghrelin administration can increase growth hormone levels in both animals and humans.

Ghrelin is a hormone that plays a crucial role in regulating hunger, appetite, and weight. It stimulates appetite by acting on the hypothalamus in the brain, decreases the release of leptin, and increases food intake. Ghrelin also plays a role in weight regulation and growth hormone secretion- a vital component of an athlete’s nutritional periodization.

Sources

Cummings D. E. (2006). Ghrelin and the short- and long-term regulation of appetite and body weight. Physiology & behavior, 89(1), 71–84. https://doi.org/10.1016/j.physbeh.2006.05.022