Cooked plantains are nutritionally very similar to a potato, calorie-wise, but contain more of certain vitamins and minerals. They’re a rich source of fiber, vitamins A, C, and B-6, and the minerals magnesium and potassium. Fiber is important because it promotes bowel regularity. Fiber softens your stool and increases its overall size and weight. Plantains contain a good amount of your daily recommended amount of vitamin C in a single cup. This vitamin acts as an antioxidant which may help boost your immune system. As an antioxidant, it may protect your body against free radical damage that’s associated with aging, heart disease, and even some types of cancer.