Eat them: Solo as a snack.
Grapefruit: The famous diet food actually lives up to its hype. In addition to being low in calories (a half grapefruit contains 37), this morning staple may banish bloat and constipation. Grapefruit also has hefty stores of vitamin C, which has been shown to fight off free-radical damage, reducing the risk of heart disease.
Eat it: Cut into slices and mixed with other citrus for a tangy fruit cocktail.