The ketogenic diet (KD) is an effective treatment for drug-resistant epilepsy, particularly in children and adolescents. It is a high-fat, low-carbohydrate diet that induces ketone production, which has anticonvulsant effects. Despite its effectiveness, the classic KD is often unpalatable, leading to poor compliance. Alternative variants, such as the medium-chain triglyceride (MCT) diet, modified Atkins diet (MAD), and low glycemic index treatment (LGIT), are more palatable and have been shown to be effective. The KD is recommended for patients with specific epilepsy syndromes, including West syndrome, Dravet syndrome, and Lennox-Gastaut syndrome. It can be used in all age groups, but most studies focus on children. The KD is generally well-tolerated, with adverse effects such as gastrointestinal issues, electrolyte imbalances, and lipid metabolism changes. However, these effects are often manageable. The KD is considered a last-resort treatment for drug-resistant epilepsy, but recent studies suggest it should be used earlier. The effectiveness of the KD varies depending on the variant and the patient's condition. While the classic KD is highly effective, the MAD is more tolerated and is often preferred for older children and adults. The KD has shown promise in treating various epilepsy syndromes, including generalized and focal epilepsies. However, long-term studies are limited, and adherence to the diet is a challenge. Despite these challenges, the KD remains a valuable treatment option for patients with drug-resistant epilepsy.The ketogenic diet (KD) is an effective treatment for drug-resistant epilepsy, particularly in children and adolescents. It is a high-fat, low-carbohydrate diet that induces ketone production, which has anticonvulsant effects. Despite its effectiveness, the classic KD is often unpalatable, leading to poor compliance. Alternative variants, such as the medium-chain triglyceride (MCT) diet, modified Atkins diet (MAD), and low glycemic index treatment (LGIT), are more palatable and have been shown to be effective. The KD is recommended for patients with specific epilepsy syndromes, including West syndrome, Dravet syndrome, and Lennox-Gastaut syndrome. It can be used in all age groups, but most studies focus on children. The KD is generally well-tolerated, with adverse effects such as gastrointestinal issues, electrolyte imbalances, and lipid metabolism changes. However, these effects are often manageable. The KD is considered a last-resort treatment for drug-resistant epilepsy, but recent studies suggest it should be used earlier. The effectiveness of the KD varies depending on the variant and the patient's condition. While the classic KD is highly effective, the MAD is more tolerated and is often preferred for older children and adults. The KD has shown promise in treating various epilepsy syndromes, including generalized and focal epilepsies. However, long-term studies are limited, and adherence to the diet is a challenge. Despite these challenges, the KD remains a valuable treatment option for patients with drug-resistant epilepsy.