2. It has high nutritional value and is rich in protein, organic acids and elements needed by human body such as calcium, phosphorus, magnesium and sodium, which are incomparable to other fruits. Grapefruit says it is extremely low in calories, so it won't get fat when eaten. Grapefruit is rich in fiber, which is easy to produce satiety. Per100g edible part, the water content is 84%, and the protein content is 0.7%. The carbohydrate content accounts for about 12%, and the heat is only 50% to 60%.