you consume more fats and very little-no carbs. 1.5-2 grams of protein per pound of bodyweight. carbs are your body's first source of energy, so when you dont consume any or very little, it will soon start using the high amounts of fats as fuel and also use your stored fat as fuel as well. if your trying to cut down, i would suggest a carb cycling diet over a keto diet. keto diets have you feeling crappy all the time. also get bad headaches from the low carbs, very moody and always in a bad mood.