Carbohydrates in Sweet Potatoes Vs. White Potatoes

People who are following a low-carb diet tend to avoid potatoes because they're starchy vegetables. But you may be wondering if sweet potatoes make a better choice, carb-wise, than white potatoes. We're here to break it down.

Potatoes aren't low-carb foods, but as it turns out, both sweet potatoes and white potatoes have about the same number of carbs per serving. Sweet potatoes are a better source of fiber and vitamins, however, and have a lower glycemic index, so they're a more nutritious choice overall.

Potatoes pack a big carb punch, given that a 100-gram serving of baked sweet potato and a 100-gram serving of baked white potato both have around 21 grams of carbs. When you count carbs on a low-carb diet, you might be more interested in net carbs, which are the digestible carbs. Net carbs are calculated by subtracting the fiber from the total carb count.

Sweet potatoes have 3 grams of fiber per 100 grams, and white potatoes have 2 grams, so their net carbs are equal to 18 grams and 19 grams, respectively. Overall, there's not too much difference carb-wise, and either potato may be a tough fit if you're following a plan that limits carbs to 20 to 50 grams a day.

Read more: Healthy Low-Carb Eating Plan

In addition to being slightly lower in net carbs, sweet potatoes also have a lower glycemic index, or GI, than white potatoes — 63 for boiled sweet potatoes versus 78 for boiled white potatoes.

The GI is a scale that measures how carbs in food affect blood sugar. Foods with a high GI cause a fast increase in blood sugar, while foods with a low GI cause only a small increase in blood sugar over a longer period of time. Maintaining more even blood sugar helps with hunger control. Baked sweet potatoes have a lower GI than baked white potatoes, and boiled white potatoes are considered a high-GI food, whereas boiled sweet potatoes are considered a low-GI food.

Read more: The Glycemic Index Table of Fruits & Vegetables

Both sweet and white potatoes may be high in carbs, but a sweet potato is the more nutrient-dense choice. A 1/2-cup serving of sweet potato provides more than 300 percent of the daily value for vitamin A and 33 percent of the daily value for vitamin C. By comparison, the white potato contains no vitamin A and has only 21 percent of the daily value for vitamin C. Both vitamin A and vitamin C support immune health and act as important antioxidants to protect your body against oxidation from free radicals.

The white potato, however, is a better source of folate, meeting 10 percent of the daily value, while sweet potatoes contain 2 percent of the vitamin. Folate supports red blood cell production and plays a pivotal role in the prevention of neural tube defects such as spina bifida during pregnancy. Both types of potatoes are a good source of the mineral potassium, while sweet potatoes have more manganese than white potatoes.

With nearly 20 grams of net carbs per serving, neither sweet nor white potato works on a very low-carb diet. But if you're consuming up to 50 to 150 grams of net carbs a day, you can fit the high-carb veggie into your diet. Mix potatoes with low-carb foods to help keep total carbs low.

Try sautéing a handful of diced sweet potatoes seasoned with paprika and cayenne. Top with fried eggs and diced avocado and you've got yourself a delicious plate of sweet potato hash that you can enjoy for breakfast or at any time of day.

At lunch, add sliced, cooked and cooled white potatoes to your salad greens and toss with vinegar and oil to create your own healthy, low-carb salad. Or roast quartered potatoes with brussels sprouts to serve as a semi-low-carb side dish with your broiled salmon at dinner.