The keto diet takes advantage of the fact that when your meals are high-fat and low-carbohydrate, there is no insulin spike, and you don't add to your fat reserves. Instead, fat from diet and stored fat are broken down to ketones ("keto" is short for "ketogenic" producing ketones). Like glucose, ketones can be used for energy, keeping your body running without increasing blood sugar or putting on excess fat. The benefits of the keto diet can be huge.