One of the most nutritious root vegetables, sweet potatoes are high in vitamins and minerals essential for healthy growth and cell development. Even when mashed as a side dish or pie filling, plain sweet potatoes lose none of their nutritional value. Adding butter or sweeteners to mashed sweet potatoes, however, introduces calories to your diet without increasing the healthful benefits of this orange-fleshed vegetable.
According to the USDA National Nutrient Database for Standard Reference, 1 cup of peeled, boiled, mashed sweet potato contains about 250 calories, 58 g carbohydrates, 89 mg sodium, 4.5 g protein and 8 g fiber. Plain mashed sweet potatoes are fat- and cholesterol-free.
Vitamins and Minerals
Sweet potatoes are excellent sources of vitamin A, vitamin C, calcium and other nutrients. One cup of plain mashed sweet potato boasts almost 40,000 mcg of beta carotene, the powerful antioxidant that the Mayo Clinic suggests may promote healthy cell growth and reduce the risk of vision problems, chronic obstructive pulmonary disease and other conditions. Of that amount, 2,581 mcg is vitamin A or retinol, essential for eye health. One cup also contains 42 mg of vitamin C, crucial for healthy muscle, skin and bones; and 89 mg calcium for strong bones and teeth.
Canned Sweet Potatoes
The nutritional profile of canned mashed sweet potatoes varies slightly from that of the freshly cooked vegetable and generally contains more salt as a preservative. According to the USDA database, 1 cup of canned mashed sweet potato offers 260 calories, 5 g protein, 59 g carbohydrates, 191 mg sodium, 5 g fiber and no fat or cholesterol.
Candied Sweet Potatoes
Candied mashed sweet potatoes, augmented with honey, maple syrup, corn syrup or brown sugar, appear in Thanksgiving casseroles and other seasonal dishes in the autumn months. A 110 g serving of mashed, candied sweet potato boasts 144 calories, 29 g carbs, 3 g fat, 8 g cholesterol, 74 mg sodium, 2 g fiber and just 1 g protein.
To get the most nutrition out of sweet potatoes, mash them with a little fat-free skim milk, vegetable broth or water for a smooth consistency and season with fresh or dried herbs. For a slightly sweeter variation, dot with heart-healthy buttery spread and a dash of cinnamon or nutmeg. If you're following a low-fat, low-sugar diet, avoid using butter, whole milk and sweeteners in the dish.