Fructose and glucose metabolism in liver cells: After several steps glucose is converted into fructose1,6-bi-phosphate. A reaction regulated by the rate-limiting enzyme phosphofructokinase, which is inhibited by ATP and citrate. Altogether the conversion of glucose to pyruvate is regulated by insulin. On the other hand, fructose, is massively taken by the liver, and converted rapidly to triose-phosphate independently of insulin control and without a feedback by ATP or citrate. A large portion of fructose is converted into glucose which can be released in the blood or stored as glycogen. A part is converted into lactate. A small portion is converted into fatty acids, which may play an important role in the development of hypertriglyceridemia and fatty liver.