1 Grapefruits help to block the absorption of carbs in the body. 2  Drinking grapefruit juice will help you to burn the stored fat. 3  Eating one grapefruit a day will help you to regulate your body and correct weight problems. 4  Grape fruits are high in enzymes which help to cut down the fat.n addition to being rich in Vitamin C, grapefruits are also rich In Vitamin A, fiber, potassium and magnesium. Additionally it contains moderate levels of Vitamin B complex such as Folate, riboflavin, pyridoxine and thiamine in addition to some resourceful minerals such as iron, calcium, copper and phosphorus.