Up Close & Edible: Sweet Potatoes

Say potato however you like. When it comes to spuds, the more important choice is not pronunciation, but variety. Although the white potato has earned a celebrated place between the turkey and the gravy, dietitians say the vitamin wealth in sweet potatoes make this less common family member a better bargain on the calories.

Sweet potatoes are not to be confused with the yam, a root similar in copper flesh, but actually from a different botanical family. The darker and sweeter yams originated from Africa and Southeast Asia. The sweet potato, meanwhile, is native to America. In supermarkets today, sellers use the names interchangeably. Ask your grocer for help distinguishing between the two. "There are significant nutritional differences," says Jennifer K. Nelson, director of Clinical Dietetics at Mayo Clinic in Rochester, Minn., and the editor of the food and nutrition section at Mayoclinic.com. "You get a bit better nutrition punch from a sweet potato, especially when it comes to beta carotene or vitamin A."

Though in recent years, protein-diet fads have banished the starchy vegetable for its carbohydrates, sweet potatoes actually rank among the healthiest vegetables, according to the Center for Science in the Public Interest (CSPI). In its 2002 comparison of nutritional values, sweet potatoes made the top 10, weighing in with significant values of beta-carotene, vitamin C, folate, potassium, phosphorous, calcium and fiber. "There are so many nutrients that accompany each calorie," says Suzanne Farrell, registered dietician and spokesperson for the American Dietetic Association. "Choose calories based on the company they keep."

White potatoes may have more folate, which helps our bodies produce red blood cells. But they also lack the beta carotenes their orange sisters offer. The antioxidant—recognizable by its trademark orange and red pigments in vegetables—could reduce the risk of chronic conditions, such as heart disease, cancer and age-related macular (eye) degeneration. "They put the white potato to shame," says Jayne Hurley, senior nutritionist at CSPI. "I would even say—and I can't believe I'm saying this—if you are a chip eater, reach for the sweet potato chips instead of the regular ones."

The sweet root contains almost twice as many calories as the white potato—about 90 calories in half a cup, compared to 57. But when incorporated into a thoughtful eating regime, it can prove a helpful dieting tool. Those trying to manage their weight should eat regularly and not exceed four hours without food. Potatoes offer an easy way to satisfy cravings and to pace yourself between meals. "That late-afternoon time slot is when a lot of good dietary intentions go out the window and people crave carbs," Farrell says. "Sweet potatoes give you that carbohydrate lift. It's a good, sweet snack and a good energy source."

And, they're easy to prepare. It only takes minimal seasoning—such as olive oil, cinnamon or some salt—to make a tasty snack. Even better, the sweet spuds provide great food for kids who usually reject vegetables. Mashed up for infants or baked as fries for older children, it provides the A and C vitamins needed for growth. Be wary, though, of drenching the vegetable in rich condiments—shy away from traditionally favorite dressings such as butter, marshmallows, sour cream and excessive brown sugar. "Maybe save that for Thanksgiving," Farrell says.