As early as 2,500 years ago, Zhang Zhongjing, the “Saint of Medicine” in the Eastern Han Dynasty, told us that our food is our medicine. The ketogenic diet is such a dietary therapy, which has been carried out in foreign hospitals for more than 90 years, and has become the preferred treatment for many types of epilepsy, including infantile spasms, as well as brain tumors and other cancers, in addition to medical treatment. According to a California researcher, 70% of cancer patients will benefit from this therapy in the future. Eating natural proteins and fats is very different from what people think, and there is a view in foreign medical circles that cancer is not entirely caused by genetic inheritance but by people’s diet and lifestyle. Therefore, doctors in Europe and the United States pay more attention to reminding people to pay attention to their daily diet and lifestyle habits than to chemotherapy. For example, doctors in German hospitals do not focus on medication, but instead spend their time guiding patients in terms of diet and lifestyle. The ketogenic diet is a medically recommended diet to fight cancer. It is a combination of high fat, moderate protein and ultra-low carbohydrate diet, also known as metabolic therapy. In layman’s terms, it is a very clean, natural diet that contains almost no carbohydrates but lots of natural protein and fat, and is sugar-free and insulated from junk food. The benefits of the ketogenic diet are that it avoids the need for high doses of drugs, chemotherapy and their side effects, and allows patients to live a normal life by giving them the hope of recovery or delaying the deterioration of their disease in many cases that cannot be solved by surgery or drugs. The ketogenic diet is quite complex in how it works. This claim of driving away cancer cells through everyday foods may sound unbelievable at first, but it is not surprising to understand how it works. Simply put, carbohydrates are converted into glucose in the body, which is the favorite source of nutrients for cancer cells to survive on, and without sugar, cancer cells can only die. The goal of this diet is to not produce sugar, so that cancer cells do not get the nutrients they need and “starve” to death. Our human cells, including cancer cells, depend on glucose for nourishment, and if sugar is taken away, normal cells can use ketone bodies as an alternative fuel, because normal cells can use both glucose and ketone bodies as fuel. This may be explained by the phenomenon of hibernation in animals such as polar bears, which eat fat and bloat in summer and fall and hide in their dens in winter, burning stored body fat and converting it into milk to nurse their cubs for up to five months without having to eat. However, cancer cells do not have this function due to structural defects, and cannot use ketone bodies to survive, and the cancer is automatically eliminated. It is not impossible for cancer cells to disappear. Medical institutions in Europe and the United States have studied the ketone diet, and now, laboratory rats and even humans have proven that it has significant effects, as confirmed by more than forty papers and research reports. In addition to most cancers, it also has an immediate effect on epilepsy, autism, depression, Alzheimer’s disease, Parkinson’s disease, sleep disorders, obesity and type II diabetes. Many terminal cancer patients have been cured by this therapy and no more cancer cells can be found in their bodies. At present, the ketogenic diet has been widely promoted and gradually recognized and applied in foreign countries, and people can easily find the required information and video materials from the news, radio, Internet and other media for understanding and learning. One of the most successful cases is Dr. Hatfield in the United States. Hatfield, a weightlifting champion, author, entrepreneur, and millionaire, is known because he came back from the dead through a ketogenic diet, which invalidated his doctor’s death sentence. At first, all three doctors declared to Hatfield that he had only three months to live and had given him a death notice. But when Hatfield heard about the ketogenic diet to fight cancer, he decided to give it a try. Although the meals were not easy to isolate from carbohydrates, this price was paid in exchange for surprising results – the cancer cells disappeared completely. In addition, ketogenic diet therapy is highly effective in the treatment of childhood epilepsy. Even for patients with refractory epilepsy who are poorly treated with antiepileptic drugs, more than half of them can be controlled by more than 50%, and if the treatment is carried out in the early stage of the disease, there is a 60% to 70% success rate, perhaps not inferior to drug treatment. In fact, this is not magic nor a miracle, but an alternative to antiepileptic drugs and epilepsy surgery. During a study at the University of South Florida, Dr. Domini, who studied metabolic therapy, found that all but a few of the patients treated with this therapy were alive. The medical community is encouraged by this exciting news, and it is also welcomed by patients, some of whom even regret that such a good therapy was not introduced sooner. Because the ketogenic diet can be used in conjunction with other cancer treatments, doctors in the United States and Canada have taken the approach of giving cancer patients medication or surgery while they are on a special diet that ensures they consume high fats and a small amount of protein. Some people are concerned about the cardiovascular risk of protein and fat intake, but they do not know that the body is most afraid of “sugar”. The Japanese book “How to fight cancer” points out that when blood flows through a tumor, about 57% of the blood sugar will be consumed by the cancer cells and become the nutrients that nourish it. The American Journal of Clinical Nutrition states that the risk of pancreatic cancer is 90 percent higher with as few as two sweet drinks a day than with those who do not. It is generally accepted internationally that the daily intake of sugar per person should be within 50 grams. However, people are often careless and consume too much sugar without being able to be ketogenic, so ketogenic recipes are very delicate and should be strictly followed by medical advice. Under normal circumstances, carbohydrates in the American diet account for 50 to 60 percent of the body’s calorie supply, fat 35 percent and protein 15 percent. But with the ketogenic diet designed for cancer patients, carbohydrates account for only 2 percent of total calories, while fats increase to 90 percent and protein to 8 percent. In his book “The Great Cholesterol Myth,” Dr. Sinatra, an American cardiologist, points out that cholesterol is definitely not the cause of heart disease; heart disease is actually inflammation of the heart, and it’s because we eat too many carbohydrates. He advocates educating and warning people about the dangers of sugar consumption and encourages people to control their carbohydrate intake in their daily lives. More and more doctors are now making the claim that “natural fats are good for humans”, even natural saturated fats such as coconut oil and animal butter are beneficial. It is important to note that the ketogenic diet is not a do-it-yourself nutritional therapy, but a major form of treatment that needs to be done carefully with medical care and family supervision. However, not all patients respond well to this therapy, and the effectiveness of treatment varies from person to person. For example, according to a study by the Johns Hopkins Treatment Center, about half of the children with epilepsy who adopted the classical ketogenic diet were able to reduce their seizure rate by no less than 50 percent within six months, and the other half showed improvement in symptoms in more than 90 percent of patients, including 15 percent who were completely seizure-free, and most families were able to gradually reduce or completely eliminate the use of anticonvulsants. Because the ketogenic diet is an unnatural form of nutritional intake, although side effects have not been overly reported abroad, it is feared that treating children with epilepsy with this diet may result in growth retardation due to protein deficiency, vitamin and mineral deficiencies, nausea, vomiting, or constipation. Postscript: Many patients have found numerous reports on the ketogenic diet for cancer treatment and come to our hospital to receive experimental ketogenic diet treatment. After evaluation, several patients with advanced cancer have been treated so far, and overall there are no serious adverse effects, the patients are well adapted and tolerated, and there is a slight decrease in tumor indicators, which is still encouraging. For patients with advanced cancer, tolerating the ketogenic diet and the family’s strict preparation of ketogenic meals every day, the efforts of patients and their families are also tremendous. The longest treated lung cancer patient started in November 2015, and so far, the family is satisfied with the treatment and willing to continue to try.