A diet that is high in fats, sufficient in proteins, and low in carbs is known as the ketogenic diet. This began as a way to treat children who have refractory epilepsy, but it has also emerged as a way for adults to lose weight. This diet makes the body consume fat instead of carbohydrates. In a normal diet, the body converts carbs from food into glucose and then sends it throughout the body, where it is very important for brain function. However, when a diet has almost no carbs, the liver turns fat into ketone bodies and fatty acids. The ketone bodies move into the brain and provide energy in the place of glucose.

As the number of ketone bodies increases in the blood, the body enters ketosis, a state in which epileptic seizures happen less frequently. However, those who are not epileptic but simply want to lose weight can use this diet as well.

The original ketogenic diet had a 4:1 ratio of fat to the combination of carbs and protein. The easiest way to do this is to eliminate carb-heavy foods, such as pasta, bread, sugar, grains, and starchy vegetables or fruits. Instead people eat foods that are higher in fat, such as nuts, as well as adding butter and cream to what they consume.

The ketogenic diet emerged in the 1920s, but the popularity of drugs that fight convulsions caused its popularity to decline. However, when Hollywood producer Jim Abrahams had a son who had epilepsy, the diet controlled the seizures. For those who are interested in weight loss only, the cyclical ketogenic diet is ideal.

Weight loss is very difficult to achieve, particularly since it requires a total transformation of one's diet and other lifestyle habits. The human body has a tendency to quickly initiate counteractive processes to regain the weight that has been lost too fast. Diets can only produce significant results when they are consistently practiced.