This is a fat-loss diet that doesn't sacrifice muscular mass. By depriving the body of carbohydrates, it forces the body into ketosis. When glucose levels are low, the body turns fat into ketones, which the brain uses as a source of energy. When there isn't enough glucose available, the body produces and burns ketones in high amounts. Carbohydrates should be limited to 30 grams per day or fewer. The advantages include that fat is burned as the body's principal fuel source. If you reduce your calorie intake, you will burn body fat quickly. You eat substantially less when you're not eating carbs. When adequate protein is ingested, this diet preserves lean muscle.