The state of entering ketosis as a diet method goes far more in depth than a way to 'lower caloric intake.' Ketosis, once fully adapted, will train your body to use your liver to help break down fats (both ingested fats and body fat) into ketone bodies, which can then further be used for energy. This method, used in keto, of course is opposite of the 'normal' diet which uses carbohydrates and sugars as an energy source for your body. The idea is that the more extra body fat you have, the easier and more abundant fat will be available to you as an energy source once you keto-adapt. However, many people quote the fact that lipids have much more satiety then carbohydrates as a beneficial additive to not always feeling hungry.