What would any soul food picnic be without sweet potato pie? The sweet potato is one of the healthiest examples of the potato world. It is a root instead of a tuber, and it is loaded with vitamin A, calcium and is great for diets as it is much lower in glycemic ratings than a regular white potato. Some feel that the potato is near perfect food and it is indeed a great boon to dieters as it is loaded with flavor and very few calories.

Sweet potatoes (Ipomoea batatas) are the root of a vine in the morning glory family and native to the New World tropics. Its history dates back to 750 B.C. in Peruvian records. Columbus brought the sweet potato to the New World from the island of Saint Thomas. The Taino word for them was batatas which eventually became patata in Spanish, patae in French, and potato in English. At that time, potato referred to the sweet potato, and not the generic white potato as it does in English nowadays. In fact, the white potato did not arrive in the northern regions from South America until the late 17th century, more than a hundred years later, according to noted food historian, Waverly Root. Some popular commercial varieties are Goldrush, Georgia Red, Centennial, Puerto Rico, New Jersey, and Velvet. 


High in carbohydrates, potatoes are a good source of protein, potassium, calcium, niacin, iron, phosphorus, vitamin C, vitamin B-6, and dietary fiber. One medium-sized potato contains about 220 calories. Most minerals in the potato are located just below the skin. For optimum nutrition, cook potatoes in their skin, or lightly peel. Eating five daily servings of fruits and
vegetables lowers the chances of cancer. A recent study found that eating nine or ten daily servings of fruits and vegetables, combined with three servings of low-fat dairy products, were effective in lowering blood pressure.

Our information courtesy of this great link to yams and sweet potatoes:
http://homecooking.miningco.com/food/homecooking/library/weekly/aa112497.htm