In many African-American families, holiday meals include sweet potatoes or yams…and often they’re prepared simmering in butter, brown and white sugar, and possibly even marshmallows. In other words, fat, sugar and more sugar. This type of preparation probably negates the incredible nutritional value of sweet potatoes. Known as a ‘superfood’, sweet potatoes are packed with fiber, Vitamin A, Vitamin C, Vitamin B6, potassium and manganese. They can also help stabilize blood sugar, which means they're a good choice for diabetics. And bonus: they're relatively low in calories (only 95 per potato)...