Ketonemia

Ketonemia is a metabolic state characterized by an elevated level of ketone bodies in the bloodstream. Ketone bodies, namely acetoacetate, beta-hydroxybutyrate, and acetone, are produced by the liver from fatty acids during periods of low carbohydrate availability or increased fat metabolism. This process is a normal physiological response to fasting, prolonged exercise, or a very low-carbohydrate diet, such as the ketogenic diet.

Normally, the body primarily uses glucose for energy. When glucose is scarce, the body switches to utilizing fat as its main energy source. The breakdown of fatty acids in the liver leads to the formation of ketone bodies, which can then be used by various tissues, including the brain, as an alternative fuel. This metabolic shift helps to spare glucose for essential functions.

Mild ketonemia is generally considered safe and is the intended outcome of ketogenic diets. However, excessively high levels of ketones can lead to a serious condition known as ketoacidosis. Ketoacidosis is most commonly associated with uncontrolled type 1 diabetes, where a lack of insulin prevents glucose from entering cells, leading to extreme fat breakdown and dangerously high ketone production. Symptoms of ketoacidosis include rapid breathing, nausea, vomiting, abdominal pain, and a fruity odor on the breath. It is a medical emergency requiring immediate treatment.