Yams and sweet potatoes are often confused, but they are not even from the same plant family. Both vegetables, however, are high-carbohydrate foods. These carbs include starches and sugar for energy and fiber for digestive health.
As it name suggests, sweet potatoes are high in sugar; just one cup or 200 grams of baked sweet potatoes contain 13 grams of sugar. The USDA Nutrient Database notes that sweet potatoes also contain 41 grams of total carbohydrates and 6.6 grams of fiber. In comparison, 200 grams of cooked yams have only about 1 gram of sugar, but have similar amounts of carbohydrates and fiber, at 55 grams and almost 8 grams, respectively.