In a nutshell, a ketone is a byproduct of burned or metabolized fat. It serves as a better alternative energy source or fuel than carbohydrates (i.e. glucose).
Ketones are produced by the liver when the body doesn’t have enough supply of carbohydrates. When blood glucose lowers, the liver breaks down fats into ketones. Ketones, then, take the role of being the body’s primary source of energy. This is the principle behind the ketogenic diet. The body loses excess weight by getting rid of carbohydrates in the diet so the body utilizes stored fats for fuel.
An Alternative Fuel Source
When you go on a low-sugar or low-carbohydrate diet, your body doesn’t get the glucose it needs to produce energy. Ketone becomes an alternative fuel source to glucose.
Ketone Benefits
Ketones are a preferred, more efficient fuel for the brain and the heart. They’re also better for your metabolism than running your body on glucose. Substituting glucose with ketone bodies can also possibly help with Alzheimer's disease.
While many people are fine with heightened ketones in the blood, it could be dangerous for those with diabetes.