A long time ago, some medical doctors discovered that seizures were reduced in patients with epilepsy when they were starving. So, doctors changed the proportion of food in the diet to achieve control of carbohydrate intake and thus reduce seizures. Studies have found that the ketogenic diet has two roles in epilepsy treatment: first, it is used for first aid and stopping seizures; second, it is used to prevent seizures from occurring through the diet. The specific mechanism of action of the ketogenic diet for epilepsy is different from that of antiepileptic drugs and consists of the following: 1. The pathway through ketone bodies: (1) Ketone bodies can inhibit glutamatergic synaptic transmission, reduce glutamate release and inhibit seizures. (2) Ketone bodies can also activate mitochondrial adenosine triphosphate (ATP)-sensitive potassium channels, and potassium ion outflow depolarizes or even supercharges nerve cells thereby reducing cell excitability. 2. Anti-epileptic effects are exerted through pathways other than ketone bodies: (1) Anti-epileptic effects are exerted by reducing carbohydrate metabolism and glycolysis; (2) Mammalian target protein pathway of rapamycin can be inhibited; (3) Brain adenosine levels can be increased and A1 receptors activated. Ketogenic diet therapy is currently aimed at all children with refractory epilepsy, regardless of age, type, syndrome, or etiology. However, except for certain metabolic disorders, including carnitine deficiency and pyruvate hydrogenase deficiency; inability to maintain adequate nutrition; having an established surgical epileptic lesion; lack of parental or guardian consent; and unqualified guardians are relative contraindications to the use of this approach.