cetogénesis

Cetogénesis is a biological process that refers to the creation of ketone bodies. Ketone bodies, also known as ketoacids, are a group of three water-soluble molecules produced by the liver from fatty acids. These molecules are acetoacetate, beta-hydroxybutyrate, and acetone. Cetogénesis primarily occurs during periods of fasting, prolonged exercise, or when carbohydrate intake is significantly reduced, such as in ketogenic diets.

The liver converts fatty acids into ketone bodies through a series of enzymatic reactions. This process is stimulated by low insulin levels and high glucagon levels, which signal that the body's glucose stores are depleted. The liver then releases these ketone bodies into the bloodstream, where they can be utilized by other tissues, including the brain, as an alternative energy source. The brain, which normally relies heavily on glucose, can adapt to using ketone bodies for up to 70% of its energy needs during prolonged starvation or carbohydrate restriction.

The production of ketone bodies helps to spare glucose for essential functions and provides an readily available fuel source for the brain and muscles. While beneficial in certain physiological states, excessive ketone body production can lead to a condition called ketoacidosis, which is a serious medical emergency. Understanding cetogénesis is important for comprehending metabolic flexibility and the body's response to different nutritional states.