Yams vs. Sweet Potatoes: What’s the Difference?
Jake Newby
| 4 min read
Key Takeaways
- Canned “yams” sold in most grocery stores in the United States are actually sweet potatoes.
- Yams contain more starch, carbohydrates and fiber than sweet potatoes, but less natural sugar.
- Unlike sweet potatoes, some yam varieties should not be eaten raw because they can contain naturally occurring compounds that may cause digestive irritation before cooking.
- As is the case with many foods, the way you prepare sweet potatoes or yams affects the nutrition you yield from them.
The difference between sweet potatoes and yams might seem like small potatoes, but it’s really not.
Botanically speaking, sweet potatoes and yams are completely different vegetables with different textures, flavors and nutritional profiles. Grocery stores sometimes label them interchangeably, so learning what separates the two can help shoppers better understand what they’re buying, preparing and eating before deciding which of these root vegetables to place in their cart.
What is a sweet potato?
Sweet potatoes belong to the morning glory family, according to the Harvard T.H. Chan School of Public Health, and are commonly grown in North and South America. Most people recognize them by their orange flesh and naturally sweet taste, though varieties can also appear white, yellow or purple. Compared to yams, sweet potatoes usually have:
- Smooth, thin skin
- Tapered ends
- Softer flesh after cooking
- A sweeter flavor
- Higher antioxidant levels
One of the main nutritional benefits of sweet potatoes is their beta carotene content. Beta carotene converts into vitamin A in the body, which helps support vision, immune health and skin function, according to the National Institutes of Health (NIH).
According to the United States Department of Agriculture (USDA), one raw, small-to-medium sweet potato contains roughly a full day’s recommended vitamin A intake. A 100-gram sweet potato also contains:
- 86 calories
- 20-22 grams of carbohydrates
- 3 grams of fiber
- Roughly 4 grams of sugar
Purple sweet potatoes may offer additional health benefits because of anthocyanins, antioxidant compounds also found in blueberries and blackberries. Research has linked anthocyanins to reduced inflammation and cardiovascular support.
What is a yam?
True yams are native to Africa and Asia and belong to the Dioscoreaceae plant family. They are less common in mainstream American grocery stores but are staples in many African, Caribbean and Asian cuisines. In the U.S., you typically have to shop at specialty stores to find them. Yams are typically:
- Larger and more cylindrical than sweet potatoes
- Less sweet than sweet potatoes
- Rough and bark-like on the outside
- Dry and starchy inside
Some yam varieties can grow several feet long and weigh over more than 100 pounds. According to USDA nutrition data, a 100-gram yam contains:
- 114-118 calories
- 26-28 carbs
- 4 grams of fiber
- 0.5-1 gram of sugar
As the comparative data suggests, yams contain more starch, carbs and fiber than sweet potatoes, but less natural sugar. While sweet potatoes have a significant edge in Vitamin A content, yams are chockful of more Vitamin C and potassium.
Unlike sweet potatoes, some yam varieties should not be eaten raw because they can contain naturally occurring compounds that may cause digestive irritation before cooking.
Why do people confuse yams with sweet potatoes?
Sweet potatoes and yams have been mistaken for each other for centuries, according to Encyclopedia Britannica. Enslaved Africans in the United States used the word “nyami” to describe sweet potatoes because they resembled familiar African yams. Over time, the word evolved into “yam.”
Later, growers in the United States began marketing soft orange sweet potatoes as “yams” to differentiate them from firmer sweet potato varieties. That labeling practice continues today, which is why canned “yams” sold in most U.S. stores are actually sweet potatoes.
Are sweet potatoes or yams healthier?
Both vegetables can support a balanced diet, but sweet potatoes stand out due to their vitamin A and antioxidant content. Yams still provide important nutrients – especially fiber and potassium – and remain a healthy source of complex carbohydrates.
As is the case with many foods, the way you prepare sweet potatoes or yams affects the nutrition you yield from them. Baking or roasting vegetables helps retain more nutrients than deep frying, according to the Academy of Nutrition and Dietetics. Both veggies can fit into a healthy diet, you just may need to shop at a specialty store if you want to get your hands on real yams.
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