How does keto work?

The ketogenic (keto) diet works by shifting your body's primary energy source from carbohydrates to fats.

Under normal circumstances, your body prefers to use glucose, which comes from the carbohydrates you eat, for energy. When you significantly reduce your carbohydrate intake on a keto diet, your body enters a metabolic state called ketosis.

The Process of Ketosis

Here's a breakdown of how this shift happens:

1. Carb Restriction: The keto diet involves drastically limiting your intake of carbohydrates. This reduces the availability of glucose as a primary energy source.
2. Switch to Fat: With glucose supply low, the body needs an alternative fuel. In keto diets, where carbs are extremely limited, the body instead draws its energy from dietary fat and the body's fat storage.
3. Ketone Body Production: When the body breaks down fat for energy, the liver produces compounds called ketone bodies (or ketones).
4. Ketones as Fuel: These ketone bodies, including beta-hydroxybutyrate (BHB), acetoacetate, and acetone, are then used by the brain and other tissues for fuel.
5. Achieving Ketosis: Utilizing fat for energy and producing ketones is the state known as ketosis. As mentioned in sources, those ketone bodies then can be measured in the blood to see if ketosis —the act of the body burning up fat instead of carbs —has been achieved.

Energy Source Comparison

Here's a simple comparison of how a standard diet and a ketogenic diet differ in their primary energy source:

In essence, the keto diet retrains your metabolism to become highly efficient at burning fat for energy by severely restricting carbohydrates, leading to the production and use of ketone bodies.