The ketogenic diet is a very low-carb, high-fat diet that shares many similarities with the Atkins and low-carb diets.

It involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbs puts your body into a metabolic state called ketosis.
When this happens, your body becomes incredibly efficient at burning fat for energy. It also turns fat into ketones in the liver, which can supply energy for the brain .

Ketogenic diets can cause massive reductions in blood sugar and insulin levels. This, along with the increased ketones, has numerous health benefits.

Some types of keto diets are-

Standard ketogenic diet (SKD)

Cyclical ketogenic diet (CKD)

Targeted ketogenic diet (TKD)

High-protein ketogenic diet
However, only the standard and high-protein ketogenic diets have been studied extensively. Cyclical or targeted ketogenic diets are more advanced methods and primarily used by bodybuilders or athletes.