Sweet potatoes provide key nutrients like beta carotene, vitamin C and potassium. They’re also a good source of fiber and can contribute to a nutrient-dense eating pattern.
The sweet potato (Ipomoea batatas) is an underground tuber.
It’s abundant in an antioxidant called beta carotene, which is highly effective at boosting blood levels of vitamin A, especially in children (1, 2, 3, 4).
Sweet potatoes are nutrient-dense, high in fiber, satiating, and tasty. They can be prepared by boiling, baking, steaming or frying.
Although commonly orange, sweet potatoes also come in white, red, pink, violet, yellow and purple varieties.
In some regions of North America, sweet potatoes are labeled as yams. This is inaccurate, as true yams belong to a different species.
Sweet potatoes are only distantly related to conventional potatoes.
This article covers everything you need to know about sweet potatoes.
Nutrition facts
The nutrient profile for 3.5 ounces (100 grams) of raw sweet potato is (5):
- Calories:86
- Water:77%
- Protein:1.6 grams
- Carbs:20.1 grams
- Sugar:4.2 grams
- Fiber:3 grams
- Fat:0.1 grams
Carbs
A medium sweet potato (boiled, skin removed) supplies about 27 grams of carbohydrates. Most of these are starches, making up roughly 53% of the carbohydrate content.
Simple sugars — including glucose, fructose, sucrose and maltose — account for about 32% of the carbs (2).
Sweet potatoes have a moderate to high glycemic index (GI), ranging from 44–96. The GI measures how rapidly a food raises blood sugar after eating (6).
Because of their relatively high GI, consuming large portions in one sitting may be unsuitable for people with type 2 diabetes. Importantly, boiling tends to yield lower GI values compared with baking, frying or roasting (7).
Starch
Starches are commonly classified into three types depending on how readily they’re digested. The starch distribution in sweet potatoes is reported as follows (8, 9, 10, 11):
- Rapidly digested starch (80%). This fraction is rapidly broken down and absorbed, contributing to a higher GI.
- Slowly digested starch (9%). This type is digested more gradually, causing a smaller rise in blood sugar.
- Resistant starch (11%). This portion resists digestion and functions like fiber, nourishing beneficial gut microbes. Cooling cooked sweet potatoes may slightly increase resistant starch.
Fiber
Cooked sweet potatoes contain a notable amount of fiber; a medium tuber offers about 3.8 grams.
The fiber is composed of soluble fibers (15–23%) such as pectin, and insoluble fibers (77–85%) like cellulose, hemicellulose and lignin (12, 13, 14).
Soluble fibers such as pectin can enhance feelings of fullness, lower calorie intake and blunt blood sugar spikes by slowing the digestion of sugars and starches (15, 16).
High intake of insoluble fibers has been linked to benefits like a reduced diabetes risk and better gut health (17, 18, 19, 20, 21).
Protein
A medium sweet potato contains about 2 grams of protein, so it’s not a strong protein source.
Sweet potatoes contain sporamins, distinctive proteins that make up over 80% of their protein content (14).
Sporamins are produced in response to physical injury to the plant and may possess antioxidant activity (22).
Although relatively low in protein, sweet potatoes are a meaningful protein source in many low-income countries (14, 23).
Summary: Sweet potatoes are predominantly carbohydrate. Most carbs are starch, followed by fiber. They’re relatively low in protein but still an important protein source in some developing regions.
Vitamins and minerals
Sweet potatoes are an outstanding source of beta carotene, vitamin C and potassium. The most plentiful vitamins and minerals in this vegetable include (24, 25, 26, 27, 28):
- Pro-vitamin A. Sweet potatoes are rich in beta carotene, which the body converts into vitamin A. Just 3.5 ounces (100 grams) supplies the recommended daily intake of this vitamin.
- Vitamin C. This antioxidant may shorten the duration of colds and support skin health.
- Potassium. Important for blood pressure regulation, this mineral may lower heart disease risk.
- Manganese. A trace mineral needed for growth, development and metabolic processes.
- Vitamin B6. Plays a role in converting food into usable energy.
- Vitamin B5. Also called pantothenic acid, this vitamin is present in small amounts across many foods.
- Vitamin E. A fat-soluble antioxidant that may protect tissues from oxidative harm.
Summary: Sweet potatoes provide abundant beta carotene, vitamin C and potassium, along with respectable amounts of several other vitamins and minerals.
Other plant compounds
As with many whole plant foods, sweet potatoes contain several phytochemicals that may influence health. These include (12, 31, 32):
- Beta carotene. An antioxidant carotenoid converted into vitamin A by the body. Consuming some fat with the meal improves absorption.
- Chlorogenic acid. The most plentiful polyphenolic antioxidant in sweet potatoes.
- Anthocyanins. Purple-fleshed varieties are rich in anthocyanins, potent antioxidant compounds.
Generally, antioxidant activity rises with the depth of flesh color. Deeply colored types — purple, intense orange and red — rank highest in antioxidant potential (1, 29, 30).
Cooking can enhance the bioavailability of vitamin C and some antioxidants in sweet potatoes, while slightly reducing other phytochemical levels (33, 34, 35, 36).
Summary: Sweet potatoes are rich in phytochemicals such as beta carotene, chlorogenic acid and anthocyanins.
Sweet potatoes vs. regular potatoes
Many people swap white potatoes for sweet potatoes, thinking the latter are the healthier option.
Both species contain similar levels of water, carbohydrates, fat and protein (5).
Sweet potatoes sometimes display a lower GI and typically contain more sugar and fiber.
Both types supply vitamin C and potassium, but sweet potatoes are notable for their high beta carotene content, which the body converts to vitamin A.
Regular potatoes may be more filling but can contain glycoalkaloids, compounds that can be harmful at high levels (37, 38).
Due to their fiber and vitamin profile, sweet potatoes are frequently regarded as the healthier choice.
Summary: Sweet potatoes are generally seen as healthier than white potatoes — they often have a lower GI, more fiber and greater beta carotene content.
Health benefits of sweet potatoes
Sweet potatoes are linked to several potential health advantages (39).
Prevention of vitamin A deficiency
Vitamin A is essential, and deficiency remains a significant public health concern in many low-income countries (40).
Deficiency can lead to reversible and irreversible eye damage and even blindness. It also weakens immune function and raises mortality risk, particularly among children and pregnant or breastfeeding women (14, 40).
Sweet potatoes are a superb source of readily absorbable beta carotene that the body can turn into vitamin A.
The depth of yellow or orange coloration correlates with beta carotene concentration (41).
Orange-fleshed sweet potatoes have been demonstrated to raise blood vitamin A levels more effectively than many other beta carotene sources, because they contain a highly absorbable form (42).
Therefore, including sweet potatoes in diets is an excellent approach to combat vitamin A deficiency in developing regions.
Improved blood sugar regulation
Disturbed blood sugar control and insulin response are hallmarks of type 2 diabetes.
Caiapo, a white-skinned and white-fleshed sweet potato variety, may improve some markers in people with type 2 diabetes.
Research suggests this variety might lower fasting blood glucose and LDL (bad) cholesterol, and improve insulin sensitivity (43, 44, 45).
However, current evidence is insufficient to recommend sweet potatoes as a treatment for type 2 diabetes; more human studies are needed (46).
Reduced oxidative damage and cancer risk
Oxidative damage to cells is linked with higher cancer risk, as cancer involves uncontrolled cell division.
Diets rich in antioxidants like carotenoids are associated with lower rates of stomach, kidney and breast cancers (47, 48, 49, 50).
Research suggests sweet potatoes’ strong antioxidant profile may reduce cancer risk. Purple-fleshed varieties show the highest antioxidant activity (14, 51).
Summary: Sweet potatoes may offer benefits such as better blood sugar control and reduced oxidative stress.
Potential downsides
Most people tolerate sweet potatoes well.
However, they contain relatively high levels of oxalates, which can raise the risk of kidney stone formation in susceptible individuals (52).
People prone to kidney stones may want to moderate their intake of sweet potatoes.
Summary: Sweet potatoes are generally safe but could increase kidney stone risk because of their oxalate content.
The bottom line
Sweet potatoes are underground tubers that supply abundant beta carotene along with many other vitamins, minerals and phytochemicals.
This root vegetable may offer several health advantages, including better blood sugar management and improved vitamin A status. For discussion of related tuber choices, see are baked potatoes healthy.
In sum, sweet potatoes are nutritious, inexpensive and simple to add to most diets.
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