The ketogenic diet is a very low-carb, high-fat diet. It is often referred to as keto.
The goal of a ketogenic diet is to keep carbs so low that the body goes into a metabolic state called ketosis.
When carb intake is very low, insulin levels go way down and the body releases large amounts of fatty acids from its body fat stores.
A lot of these fatty acids are transferred to the liver, which can turn them into ketone bodies.
Ketone bodies, or ketones, are water-soluble molecules that can cross the blood-brain barrier and supply energy for the brain.
Instead of running on carbs, the brain starts running largely on ketones. The little glucose still required by the brain can be produced by the body via a process called gluconogenesis.
Some versions of a ketogenic diet even restrict protein intake, because too much protein may reduce the amount of ketones produced in some people.
A ketogenic diet was traditionally used to treat drug-resistant epilepsy in children. It may also have benefits for other neurological disorders, and metabolic problems like type 2 diabetes.
It has also become popular for fat loss, even among some bodybuilders. It is a very effective diet to lose fat, and tends to cause a major reduction in appetite (11, 12).
A ketogenic diet involves high-protein, high-fat foods. Carbs are generally limited to less than 50 grams per day, and sometimes to less than 20–30 grams.
A conventional ketogenic diet is referred to as a “standard” ketogenic diet (SKD).
However, there are other variations that involve strategically adding carbs:
Bottom Line: A ketogenic diet, or keto, involves reducing carbs sufficiently to induce a metabolic state called ketosis. It is a very powerful diet to lose fat, and has powerful benefits for several diseases.