All berries are great sources of fiber—a nutrient that most Americans don’t get enough of and one that is important for a healthy digestive system. Fiber may help to promote weight loss. Raspberries boast the most at 8 grams per cup—and also contain ellagic acid, a compound with anti-cancer properties. The same amount of blueberries has half the fiber (4 grams), but is packed with anthocyanins, antioxidants that may help keep memory sharp as you age. A cup of strawberries contains 3 grams of fiber, but more than a full day’s recommended dose of skin-firming vitamin C.