Once you're keto adapted, your body uses ketones for energy rather than glucose. (queenketo.com)
In a healthy person, the production of ketones for energy is the body's natural response to starvation, so this happens when dieting, overnight and during fasting. (thomasdelauer.com)
As your body draws on ketones for energy, you'll effectively enter and strive to stay in ketosis. (lifesum.com)