Not all ketogenic diets have the same effects. The kind of fats you eat could make a difference, according to new research in Science Advances. The point of a ketogenic diet is to induce a state called ketosis, in which the body uses fat as its main fuel source. That's why keto diets involve restricting carbohydrates. Ketosis happens when the body is short on glucose. While keto diets are probably best-known as a strategy for weight loss, they were originally designed to treat epilepsy.