Keto Core Max : Department of Agriculture, one medium-sized pear has 27 g of carbs. The keto diet aims to flip your metabolism into ketosis, a metabolic state in which your body burns fat instead of carbs for energy. This guidebook teaches you about how many grams of protein, fat, and carbs you’re eating each day and how to calculate your macros to stay in ketosis. Some people on a very restrictive low-carb diet, such as the ketogenic diet, are usually limited to 20 g or less of carbohydrates per day.