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Emergence of hunger   theories

Emergence of Hunger - Theories

These two theories are considered complementary, but are not mutually exclusive. It’s believed that the glucostatic theory explains the beginning and end of a meal, or in other words, the short-term feeding regulation. The lipostatic theory explains the long-term regulation of feeding


There are two interesting theories based on a premise of existing fixed levels of energy. It says that feeding is a medium by which physical energy returns to its optimal level – hence the adjective fixed. Researchers in the 1940s and 1950s were thinking on what they could base this regulation. Some of them assumed that feeding is regulated by a system which maintains appropriate levels of glucose in the blood. According to this point of view, we feel hunger when levels of glucose drop significantly below that level.


Glucostatic theory


They coined it as the glucostatic theory and it’s completely logical if we take into consideration that glucose is the main source of energy for our brains. Two observations support this theory. The first one noticed that an increase of glucose levels in the blood simultaneously boosts electric activity measured in our center for satiety and decreases activity measured in our center for hunger. The second fact was observed in the brain center in charge of satiety. The researchers noticed that it concentrated amounts of glucose, while other areas of the hypothalamus didn’t.


Lipostatic theory


The other theory based on the concept of fixed levels is the lipostatic theory. It says that humans have a fixed level of fat in the body. Deviations from that level lead to food consumption so that the amount of fat can return to the fixed level. If the amount of fat tissue increases, ingestion decreases. According to this, physiologists perceive that products of fat metabolism mostly manage long-term feeding control. The fact that adult body weight remains relatively stable through the years is in favor of this idea.


These two theories are considered complementary, but are not mutually exclusive. It’s believed that the glucostatic theory explains the beginning and end of a meal, or in other words, the short-term feeding regulation. The lipostatic theory explains the long-term regulation of feeding.


Disadvantages?


However, we should address some disadvantages to these theories. They’re not in complete accordance with the basic evolutionary assumptions about feeding and the main predictions still lie unconfirmed. They don’t take into consideration the influence of important factors, such as flavor, learned experiences and social environments.