A white potato is a tuber with an edible plant but inedible leaves. Sweet potatoes are another species of tuber with leaves that are edible and nutritious.
In general, sweet potatoes are healthier than white potatoes. Sweet potatoes offer 4 grams of fiber and 2 grams of protein, while white potatoes have 3 grams of fiber and 3 grams of protein. Sweet potatoes offer more potassium, magnesium, calcium and manganese than white potatoes. Only white potatoes have iron, however. Sweet potatoes also offer higher concentrations of vitamins A and C.
White potatoes have about 130 calories, whereas sweet potatoes have 90. Additionally, white potatoes have about 29 grams of carbohydrates, while sweet potatoes have 24. Sweet potatoes and white potatoes have 7 and 2 grams of sugar, respectively.
The flesh of either potato varies from white to orange to purple. There are 4,000 known varieties of white potato and 5,000 known varieties of sweet potato. However, potatoes sold in the United States tend to be white or light golden. Sweet potatoes in the U.S. tend to be golden-orange. Both originated in Central and South America.
Some potato varieties are mealy because they have more starch, making them ideal for baking or mashing. Potatoes with less starch are considered waxy. Sweet potatoes also vary by sugar and moisture levels.