Grapefruit is a nutritious citrus fruit that is about the size of a large orange. It is an excellent source of vitamins A and C, as well as potassium and fiber. Grapefruit is also low in calories and has been shown to aid in weight loss. This fruit can be eaten as a breakfast topping, in salads, or as a snack. However, grapefruit can interact with certain medications, so it is important to consult with a doctor or pharmacist before consuming it if you are taking any medication.