Acetyl coenzyme A (acetyl-SC0A) is a molecule that has a key role in several fundamental metabolic processes. The reaction of converting pyruvate into acetyl-SCoA creates a link between glycolysis and the citric acid cycle. Acetyl-SCoA, which is the product of fatty acid oxidation, enters the citric acid cycle only when there is a balance between fat and carbohydrate degradation. During starvation or in case of diabetes, oxaloacetate is used for the synthesis of glucose via the process of gluconeogenesis, hence it lacks for condensation with acetyl-SCoA. Under these conditions, acetyl-SCoA is directed towards the synthesis of acetoacetate and D-3-hydroxybutyrate. Ketone bodies are transmissible forms of acetyl units, produced by the liver for the purposes of extrahepatic tissues. In the peripheral tissue, ketone bodies are degraded to acetyl-SCoA. Deficient in carbohydrates, the organism switches to the metabolism of fat. The product of fatty acid degradation is acetyl-SCoA, which is then directed towards the production of energy. Insulin allows glucose to permeate from the blood into the body’s cells and to accelerate glycolysis in the liver resulting in the production of acetyl-SCoA, which will lead to further synthesis of fatty acids. Diabetes is a complex disease, characterized by an intense disorder of the metabolic fuel usage: it is an excessive production of glucose in the liver and its insufficient use in other organs.