Ketohexokinase (KHK) is a key enzyme in fructose metabolism, converting fructose into fructose-1-phosphate. There are primarily two isoforms: KHK-C, the active form, and KHK-A, the low-activity form. KHK is highly expressed in tissues such as the liver and kidneys, regulating the metabolism of fructose after its intake. Its activity impacts energy balance, lipogenesis, and uric acid production, and is associated with metabolic diseases such as metabolic syndrome, non-alcoholic fatty liver disease (NAFLD), and diabetes. Specific expression and mutations in the KHK gene may lead to abnormalities in fructose utilization, affecting health status. Studying the activity and regulatory mechanisms of KHK is crucial for understanding metabolic diseases.