Sweet potatoes are root vegetables harvested in warm climates, including Central and South America and some southern North American states. Overall, they’re healthy vegetables that are low in sodium, fats and cholesterol and a good source of fiber and vitamins A, B-6 and C. Sweet potatoes might not fulfill everyone’s nutritional needs, however. Compared to other vegetables, they can be high in calories and carbohydrates and are missing some key vitamins.
Sweet Potato Calories
According to the U.S. Department of Agriculture National Nutrient Database, a medium baked sweet potato contains 103 calories. That amount can go up depending on how you prepare the vegetable. Sweet potato French fries contain about 160 calories per serving. Mashed sweet potatoes contain 258 calories per cup. While the calorie content is not astronomical, you will benefit more from avoiding sweet potatoes if you are on a low-calorie diet. By comparison, broccoli has 31 calories per cup, and green beans have 27 calories per cup.
Lacking in Vitamins
Key vitamins missing from sweet potatoes include D and B-12. Vitamin D is an essential nutrient that can help prevent osteoporosis by promoting the absorption of calcium. According to the Office of Dietary Supplements, vitamin D helps regulate muscles and nerves and aids the immune system in fighting off bacteria and viruses. Vitamin B-12 helps produce red blood cells and regulates the nervous system. Eating sweet potatoes does not cause a vitamin deficiency, but if your diet is low in these nutrients, you might need to take a supplement to prevent a deficiency from developing. Talk to your doctor before taking any new vitamins. On the other hand, a medium sweet potato does contain excessive amounts of vitamin A, with more than 500 times the recommended daily intake according to the National Institutes of Health Office of Dietary Supplements. A prolonged consumption of vitamin A from beta-carotene sources, such as a sweet potato, may cause your skin to turn orange or yellow. Your skin will return to normal once you lower your intake, according to MedlinePlus.com.
High Number of Carbohydrates
A medium baked sweet potato -- 114 grams -- contains 24 grams of carbohydrates. Carbs are a main source of energy for the body. Too many, however, can cause your body to convert carbs into fat. The USDA Dietary Guidelines for Americans 2010 recommends getting 45 to 65 percent of your daily calories from carbohydrates, roughly 225 to 325 grams per day. A baked sweet potato accounts for 8 percent of the recommended daily allowance, or RDA, but 1 cup of mashed sweet potatoes -- 255 grams -- contains 59.2 grams of carbs, about 20 percent of the RDA. If you’re an athlete, a diet high in carbs can increase energy. The downside to a high-carb diet is that the nutrient may up your risk for heart problems. In a 2009 "Journal of the American College of Cardiology" study researchers from Tel Aviv University's Sackler School of Medicine found that a high-carb diet distends arteries for several hours, which over time can reduce vein elasticity and cause heart disease or sudden death.
Naturally occurring sodium content in a baked sweet potato is actually very good -- 41 milligrams, or 2 percent of the RDA. Mashed sweet potatoes and French fried sweet potatoes, however, have the potential to be very high in sodium, depending on how much salt you add while cooking them. MedlinePlus.com reports that sodium is vital because it helps you maintain a healthy balance of fluids. Too much, however, can increase blood pressure and up your risk for heart disease and stroke. Healthy adults should consume no more than 2,300 milligrams per day; 1,500 milligrams for those over the age of 50 or have chronic heart disease, blood pressure or kidney disease. The USDA nutritional database and recipes on the EatingWell website show that mashed sweet potatoes contain 191 milligrams of sodium and that oven-baked sweet potato fries have 323 milligrams.