The ketogenic diet (or keto for short) is a low-carbohydrate, high-fat dietary regimen designed to induce ketosis – the breakdown of body fat into ketones. This mechanism allows the body to largely function using ketones as biological "fuel" instead of glucose.

Essentially, in the ketogenic diet, the main source of energy for the body is fat instead of carbohydrates. Many nutrient-dense foods, such as fiber and vitamins, contain high amounts of carbohydrates, like whole grains, fruits, and vegetables. Carbohydrates in this dietary scheme are limited, so foods such as bread, cereals, and pasta are consumed in minimal amounts, and the same applies to the consumption of fruits and vegetables.