Beta-hydroxybutyrate (BHB), also known as β-hydroxybutyrate, is one of the three ketone bodies produced by the liver during periods of low glucose availability, such as fasting, prolonged exercise, or adherence to a ketogenic diet. Ketone bodies serve as alternative energy sources when glucose levels are insufficient to meet the body’s energy demands.
Elevated levels of beta-hydroxybutyrate in the blood, a state known as ketosis, occur during fasting, prolonged exercise, or adherence to a low-carbohydrate, high-fat ketogenic diet. Ketosis is characterized by increased fat oxidation and ketone body production to provide energy in the absence of sufficient glucose.
Beta-hydroxybutyrate is synthesized in the liver from acetyl-CoA, primarily derived from fatty acids through a process called ketogenesis. During periods of low carbohydrate intake or fasting, insulin levels decrease, leading to increased fatty acid breakdown and subsequent production of ketone bodies, including beta-hydroxybutyrate.