Does it matter whether one eats a sweet potato or a white potato? "Glycemic Index" is a measure of the potential hazard from the carbohydrates when you eat a particular food based, on 50 grams of Useable Carbs from that food. Glycemic Load is the application of the glycemic index to a standard serving of particular food, which might be more or less than 50 grams of carbs. The higher the glycemic load of a food, the more likely it is to cause you to develop diabetes eventually. The Glycemic Load of a Sweet Potato is 17. The Glycemic Load of a baked potato is 26. For comparison, glycemic load of white rice is 30, glycemic load of an apple is 6.
The fiber content of a baked potato is 4.2 grams/serving. A sweet potato has 4. I have not been able to find why the Glycemic Load of a sweet potato is so much lower, thus healthier to eat, in addition to having vitamins and minerals lacking in a white potato.
Though vitamin content can vary with different varieties, an average-sized sweet potato tuber contains a whopping 15,000 international units of vitamin A and about half as much vitamin C as an orange. Added to that are worthwhile amounts of protein, calcium, magnesium, iron and carotene, and practically no fat. In fact, sweet potatoes are one of the few vegetables capable of providing the full nutritional needs of human beings. In Japan, where sweet potatoes are the second most important crop, they've long been a popular ingredient both in stir-fry and tempura dishes.
The Potato is an edible starchy tuber. It is produced by certain plants of a genus of the nightshade family, especially the common white potato (Solanum tuberosum).
Unrelated genetically is the sweet potato, Ipomoea batatas; family Convolvulaceae, which is native to tropical America.
(Link: Potatoes; added 6/2009)