Ketogenic Diet The ketogenic, or "keto," is a low-carbohydrate, high-fat diet that has been used for centuries to treat various medical conditions. The ketogenic diet was widely used to help control diabetes in the nineteenth century. It was introduced in 1920 as an effective treatment for epilepsy in children who had failed to respond to medication. The ketogenic diet has also been studied and used in cancer, diabetes, polycystic ovary syndrome, and Alzheimer's disease. The ketogenic diet, on the other hand, is notable for its exceptionally high-fat content, typically 70% to 80%, with only a moderate intake of protein. Because it cannot store glucose, the brain requires the most glucose in a steady supply, about 120 grams daily. Fasting, or eating very little carbohydrate, causes the body to draw stored glucose from the liver and temporarily break down muscle to release glucose. If this continues for 3–4 days and the body's stored glucose is completely depleted, blood levels of a hormone called insulin fall, and the body begins to use fat as its primary fuel. Ketone bodies are produced by the liver from fat and can be used in the absence of glucose. Ketosis occurs when ketone bodies accumulate in the blood. Mild ketosis occurs naturally in healthy people during periods of fasting (e.g., sleeping overnight) and very strenuous exercise.
Ketogenic Diet. Proponents of the ketogenic
diet claim that if the diet is strictly followed, blood levels of ketones should
not rise to dangerous levels (known as "ketoacidosis") because the brain uses
ketones for fuel and healthy people produce enough insulin to keep excessive
ketones from forming. The rate at which ketosis occurs and the number of ketone
bodies that accumulate in the blood differ from person to person and are
determined by factors such as body fat percentage and resting metabolic rate.
Popular ketogenic resources generally recommend an average of 70–80% fat from
total daily calories, 5–10% carbohydrate, and 10–20% protein. This equates to
approximately 165 grams of fat, 40 grams of carbohydrates, and 75 grams of
protein for a 2000-calorie diet. Because eating too much protein can prevent
ketosis, the protein amount on the ketogenic diet is kept moderate in comparison
to other low-carb, high-protein diets. Protein amino acids can be converted to
glucose, so a ketogenic diet includes enough protein to maintain lean body mass,
including muscle, while still causing ketosis. A long-term ketogenic diet has
been linked to an increased risk of kidney stones and osteoporosis, as well as
higher uric acid levels in the blood (a risk factor for gout). Nutrient
deficiencies may occur if the ketogenic diet does not include a variety of
recommended foods. To ensure adequate intakes of fiber, B vitamins, and minerals
(iron, magnesium, and zinc)—nutrients typically found in foods like whole grains
that are restricted from the diet—it is critical to include a daily variety of
the allowed meats, fish, vegetables, fruits, nuts, and seeds. Because whole food
groups are excluded, working with a registered dietitian to develop a ketogenicdiet that minimizes nutrient deficiencies may be beneficial.
