Skip to Content

Are Sweet Potatoes and Yams the Same Thing?

are sweet potatoes and yams the same thing

When I was growing up I always remember yams had bulges in the skin and looked much different from a sweet potato.

But, I noticed that in the USA they call sweet potatoes yams.

I wanted to know if they’re the same thing so I did some research into the origins of the words and what they mean, and here’s what I found.

Sweet potatoes and yams are not the same thing.

In the USA the word yam is used to refer to sweet potatoes but they are from a different botanical family.

Sweet potatoes and yams are root vegetables that share similar characteristics so the name yam was used, and ever since has remained.

Today, I’ll share the origins of the word yam, how yams and sweet potatoes differ.

Interestingly, the word yam is used to refer to various different vegetables in different countries around the world, so I’ll explain what vegetables these are too.

Sweet Potato vs Yam Nutrition

Sweet Potato vs Yam Nutrition

Since sweet potatoes and yams are different vegetables.

I wanted to know how they compare the nutrients they contain.

And whether one is healthier than the other.

Here’s a summary of the nutritional differences between yams and sweet potatoes.

Sweet potatoes are as healthy as yams.

They both contain a fair amount of vitamins and minerals.

Sweet potatoes are higher in some nutrients, whereas yams are higher in others.

The major differences are the amount of Vitamin C, potassium, fiber, and sugar.

Details are provided below.

I’ve compiled a table that shows a side-by-side comparison of the nutrients (vitamins and minerals) found in sweet potatoes and yams.

Nutrient Yams Sweet Potatoes
Protein 3.06% 3.14%
Fat 0.39% 0.11%
Fiber, total dietary 16.40% 12.00%
Sugars, total including NLEA 2.08% 17.42%
Calcium, Ca 0.68% 1.20%
Iron, Fe 0.01% 0.01%
Magnesium, Mg 5.25% 6.25%
Phosphorus, P 7.86% 6.71%
Potassium, K 17.36% 7.17%
Sodium, Na 0.39% 2.39%
Zinc, Zn 2.18% 2.73%
Copper, Cu 12.71% 10.79%
Manganese, Mn 19.85% 12.90%
Selenium, Se 0.01% 0.01%
Vitamin C, total ascorbic acid 19.00% 2.67%
Thiamin 11.20% 7.80%
Riboflavin 2.46% 4.69%
Niacin 3.45% 3.48%
Vitamin B-6 2.25% 1.61%
Vitamin B-12 0.00% 0.00%
Vitamin A 0.78% 78.78%
Vitamin E 23.33% 17.33%
Vitamin D 0.00% 0.00%
Vitamin K 0.23% 1.80%

(source: USFDA)

Particularly nutrients of note are:

These vary quite a bit between sweet potatoes and yams.

Sweet potatoes have significantly more sugar.

Whereas, yams have significantly more vitamin C, potassium, and fiber than sweet potatoes.

As you may know, all foods have different levels of nutrients.

Which is a key reason why dieticians and nutritionists recommend eating a varied diet.

That way foods you eat that are high in some nutrients and low in others will be balanced out by other foods that have more or less of the nutrients which are lacking or abundant in others.

However, to say for sure which is healthier depends on vitamins and minerals you’re lacking in if any.

And to know that you’ll need to have a blood panel did that can look at various markers which will show whether you need to consume more or less of a particular type of food.

Origin of the word yams and how sweet potatoes are called yams

According to an official source, the word yam is derived from a Spanish and Portuguese word that was likely adapted from an African word in the 1500’s.

As the yam is thought to be native to the African continent.

It’s believed that the people in Spain and Portugal would often trade with the countries in what is now Africa and the word was a shared word used between them.

The Spanish word of the root vegetable known as yams is ‘igname’, and the Portuguese word is ‘inhame’.

In the African language known as Twi the word is ‘anyinam’.

In English, the beginning vowel ‘i’ or ‘a’ was dropped to produce a word that sounded very similar and was spelled ‘yam’.

This is thought to have occurred as African people arrived in the USA when slavery was a common practice.

Yams, according to Encyclopedia Britannica and botanically distinct from sweet potatoes, and are in a different botanical family – Dioscoreaceae.

Whereas, sweet potatoes are in the Convolvulaceae botanical family.

Different vegetables that the word ‘yam’ is used for around the world

Yam is not only used for a vegetable that isn’t a yam in the USA.

Here’s some countries and the vegetable that has the name yam:

  • New Zealand – an oca tuber
  • Malaysian and singapore – the word for taro
  • Japan – sweet potato

I’ve personally tried ‘yams’ in New Zealand.

They have a tart taste and are equally as delicious as sweet potatoes.

They are however, much smaller, about 1 inch (2.5 cm) in diameter and 3 to 4 inches long (7.5 cm to 10 cm). And have a red skin when raw.

Carbs in Yams vs Sweet Potatoes

Carbs in Yams vs Sweet Potatoes

Carbs or carbohydrates are naturally occurring chemicals in foods and are often limited to help with weight loss.

Or to keep one from putting on weight.

So, which has the most carbs, yams or sweet potatoes?

Sweet potatoes have 74% of the carbs that yams have.

Therefore, sweet potatoes have lower carbs.

Sweet potatoes on average contain 20g of carbs per 100g (3.4 oz) which is about half a cup, whereas sweet potatoes 27g according to dietician Leslie Beck.

So, if you’re trying to reduce the number of carbs you eat then sweet potatoes are a better option than yams.

Another way to describe foods that are low in carbs is by referring to a measurement known as a glycemic index.

I explained what vegetables have the lowest glycemic index.

And provide a list of high, medium, and low carb – or glycemic index vegetables in this article about whether legumes are low-glycemic.

Do Yams or Sweet Potatoes Have More Sugar?

Do Yams or Sweet Potatoes Have More Sugar

Sugar intake is important to monitor as too much can lead to various health issues.

So, I looked into the naturally occurring sugar content of sweet potatoes and yams to see which has more.

Here’s the answer.

Sweet potatoes have more sugar than yams.

Yams are particularly low in sugar and contain 4.16% of your recommended daily intake of sugar per 200g (6.8 oz), which is a reasonably sized serving.

The same amount of sweet potatoes contain 34.8% of your recommended daily intake of sugar.

There is a study quoted by Harvard Medical School that showed that 5 servings of fruits and vegetables a day is the same as eating more than that.

For example, if you eat 6 or 7 servings of fruits and vegetables per day it’s not any better for you than eating 5.

However, eating less than that increased the chance that a person would get a disease that would cause mortality.

So, about 5 servings of fruits and vegetables a day is the minimum you should aim to consume.

But, there is also a recommended daily intake of sugar.

Which is 24g for women, and 35g for men.

Therefore, you need to select what fruits and vegetables you eat based on their sugar content.

Sweet potatoes contain 8 grams of sugar for a normal serving size of 1 cup (200g), 3.4 oz.

And an average serving of fruit contains anywhere from 5g to 15g of sugar.

Therefore, to make sure you don’t consume too much sugar, you need to know the sugar content of the 5 or more fruits and vegetables you consume.

As well as, other foods you eat to ensure you’re not consistently going over the recommended sugar intake.

Then you can make a decision about whether the sugar content of yams and sweet potatoes is a factor that would influence whether you eat one over the other.

And varies from person to person based on their diet.

Are Yams Good for Diabetics to Eat?

Are Yams Good for Diabetics to Eat

Diabetics need to monitor their sugar intake and generally consume a low sugar diet.

Therefore, I was interested in whether yams are good for diabetics to eat, and looked into it.

Here’s what I found.

In general, yams are good to eat for diabetics.

Yams contain fairly low amounts of sugar.

A typical serving of yams contains 4% of your recommended daily intake of sugar.

Therefore, yams won’t considerably add to the total sugar you eat in a day.

Yams can be considerably better than sweet potatoes for diabetics because sweet potatoes have much higher sugar content.

Sweet potatoes contain 8 grams of sugar for a normal serving size of 1 cup (200g), 3.4 oz which is equivalent to 17.42% of the recommended daily sugar intake.

Which is 4 times more than the sugar content of yams.

However, depending on what other foods you eat sweet potatoes can also be fine for diabetics.