Have you ever heard about grapefruit diet? I think grapefruit all day isn’t a well-balanced diet. But eating grapefruit can really help you to lose weight. A research has found that eating a half a grapefruit before every meal can help you lose up to a pound a week! The thing is that grapefruit is high in fiber and low in calories, and there are only 37 calories in a half a grapefruit!