Yam and sweet potato are not the same thing. They come from two completely different plants, that are not even from the same family. Yams have a savoury taste, that reminds of cassava or regular potato, while sweet potatoes are much sweeter, like pumpkin.

The terms "yam" and "sweet potato" are often used interchangeably, causing lots confusion. So here are the main differences and similarities between yams and sweet potatoes.

Yam vs Sweet Potato: Basic Differences

Yams have a rough, textured brown skin that looks a bit like tree-bark, while sweet potatoes normally have a thin orange-brownish skin. 

Calories in Yams vs. Sweet Potatoes

Yams contain less carbs and less calories than sweet potatoes. In addition to that, yams have slightly more fiber, compared to sweet potatoes. All of this makes yams more suitable for weight loss diets.

Why are sweet potatoes often wrongly labeled as yams?

Some varieties of sweet potatoes are often wrongly labeled as yams. This is usually the case with "softer" varieties of sweet potatoes, which become very soft when cooked. 

Enslaved Africans were probably the first to refer to sweet potatoes as yams, because the potatoes reminded them of the yams they knew in Africa. In the 1930s when a new sweet potato variety was cultivated, people started referring to it as yam. This was to distinguish it from other earlier sweet potato varieties.

Yam vs Sweet Potato: Nutritional Comparison

Real yams normally contain slightly less calories than sweet potatoes. This is mainly because sweet potatoes being “sweet”, naturally contain more sugar. Yams also contain more dietary fiber. 

When it comes to fat and protein content, the yams and sweet potatoes are very similar. Both foods have a very low fat content and no cholesterol.

Nutritional content of 100 g (around 3.5 oz) of raw yams compared to sweet potatoes.

How to know for sure if you are buying a yam?

The majority of “yams" in American supermarkets are actually sweet potatoes. But because of regulations from the U.S. Department of Agriculture, the label "yam" should be accompanied with “sweet potato” if the product is not a real yam. If you want to find an actual yam, you probably have to go to a grocery store that specialises in international food.

Yam vs Sweet Potato: Taste Differences

Yams and sweet potatoes taste very differently.

• While yams have a neutral-savoury that is similar to potatoes, sweet potatoes have a higher sugar content and are much sweeter. 

• The flavour of yams is mild and earthy, while sweet potatoes are naturally sweet and have a similar flavour to pumpkin.

• The texture of yams is much dryer and starchier, while sweet potatoes are usually softer and creamier when cooked. 

• Yams are mostly suitable for savoury dishes, while sweet potatoes are used both in sweet and savoury recipes.

Yam vs Sweet Potato: Vitamins and Minerals

Both yams and Sweet potatoes are excellent sources of micronutrients. Sweet potatoes usually contain more vitamin A and beta-carotene, while yams contain more vitamin C.

The table below summarises the vitamins, minerals and some other nutrients present in 100 g (around 3.5 oz) of raw yams compared to sweet potatoes.

Yam vs. Sweet Potato: Uses

Both yams and sweet potatoes can be boiled, roasted, fried, steamed, etc. but the final result will taste differently, depending on which vegetable you used.

In most recipes, it is not a good idea to substitute yams with sweet potatoes, or the other way around. If you were to substitute a sweet potato with a yam, the result would be very much similar to using regular potatoes in the dish.