Which Has More Fiber, Yam or Sweet Potato?

November 28, 2025 •

3 min read

According to comparative nutritional data, true yams typically contain slightly more fiber per 100g serving than sweet potatoes. This article breaks down the nutritional content of these two distinct vegetables, revealing the key differences that go far beyond just their fiber count.

Quick Summary

This nutritional guide compares the fiber content of yams and sweet potatoes, two distinct vegetables. Learn which one has more dietary fiber, alongside other important nutritional and flavor differences.

Key Points

Yam Has More Fiber: Per 100g, true yams typically contain slightly more dietary fiber than sweet potatoes.
Sweet Potatoes Excel in Vitamin A: Sweet potatoes are exceptionally rich in beta-carotene, which converts to Vitamin A, a nutrient found in very low levels in true yams.
Yams Provide More Potassium: Yams offer a higher concentration of potassium, a mineral crucial for regulating blood pressure.
Different Flavors and Textures: True yams are starchy and mild-flavored, whereas sweet potatoes are naturally sweeter and moister.
Common Confusion: In the U.S., the term 'yam' is often used incorrectly to describe orange-fleshed sweet potatoes, which are a different species.
Both are Healthy: Despite their differences, both vegetables are excellent sources of nutrients and can be a healthy part of any diet.

Yam vs. Sweet Potato: The Fiber Showdown

When comparing the fiber content of yams and sweet potatoes, the short answer is that true yams hold a slight advantage on a gram-for-gram basis. For example, a 100g serving of raw yam provides about 4.1 grams of fiber, while the same amount of raw sweet potato offers around 3 grams. This difference, though small, is consistent whether the vegetables are raw or cooked.

Dietary fiber is essential for maintaining a healthy digestive system, aiding in bowel regularity, and preventing constipation. The type of fiber is also important. Yams are known for having a higher content of resistant starch, which behaves like soluble fiber and feeds beneficial gut bacteria, contributing to overall digestive health. Both vegetables contain a mix of soluble and insoluble fiber, but their overall nutritional profiles diverge significantly in other areas.

A Deeper Look at the Nutritional Profiles

While fiber is a key metric, it's not the only factor to consider when choosing between a yam and a sweet potato. Their most dramatic nutritional differences lie in their vitamin and mineral content.

Where Sweet Potatoes Shine

Vitamin A and Beta-Carotene: Sweet potatoes are a powerhouse of Vitamin A, primarily in the form of beta-carotene, an antioxidant that gives them their vibrant orange color. This is a critical nutrient for vision, immune function, and skin health. In contrast, true yams contain very little of this nutrient.
Vitamins and Minerals: Sweet potatoes generally contain more Vitamin C, calcium, and iron compared to yams.

Where Yams Excel

Potassium: Yams contain substantially more potassium than sweet potatoes. This mineral is vital for blood pressure regulation and muscle function.
Vitamin C and B6: In addition to fiber, yams are a better source of Vitamin C and Vitamin B6 than sweet potatoes.

The Identity Crisis: What You're Actually Buying

In the United States, grocery store labeling often leads to confusion. The orange-fleshed root vegetable commonly sold as a "yam" is almost always a variety of sweet potato. True yams are a different plant species, typically imported from Africa or the Caribbean, and are distinguished by their rough, bark-like skin and starchier, less sweet flesh. For accurate nutritional comparison, it's crucial to understand the difference between the two.

Nutritional Comparison Table (per 100g, raw)


Nutrient	Sweet Potato	Yam
Calories	~90 kcal	~116 kcal
Carbohydrates	~20g	~28g
Dietary Fiber	~3g	~4.1g
Protein	~1.6g	~1.5g
Fat	~0.05g	~0.17g
Sugar	~4.18g	~0.5g
Vitamin A	~14,187 IU	~138 IU
Vitamin C	~2.4mg	~17.1mg
Potassium	~337mg	~816mg

Culinary Considerations and Preparation

The differences in their composition affect how yams and sweet potatoes are best prepared and what they taste like. Sweet potatoes are sweeter and moister, making them ideal for dishes where their flavor can shine.

Cooking with Sweet Potatoes

Baking: Perfect for roasting whole or as fries due to their natural sweetness.
Mashing: Creates a creamy, sweet purée ideal for side dishes.
Desserts: Used in pies, casseroles, and other sweet treats.

True yams, with their starchy and mild flavor profile, are more akin to a traditional potato.

Cooking with Yams

Boiling/Steaming: Excellent for creating a smooth, starchy paste or for serving with savory dishes.
Frying: Can be used for savory fried chips or wedges.
Stews/Soups: Holds its shape well and adds a starchy body to dishes.

Both vegetables offer a high nutrient density and can be incorporated into a balanced diet. The best choice depends on your specific nutritional goals and flavor preferences.

Conclusion: Making the Right Choice for Your Diet

While yams technically contain more fiber than sweet potatoes, the overall nutritional story is more complex. Sweet potatoes provide a significant boost of Vitamin A, while yams offer a superior amount of potassium. Both are excellent, low-fat sources of complex carbohydrates, fiber, and other essential nutrients, contributing to good digestive and overall health. Therefore, the better choice isn't a matter of which is strictly superior, but rather which vegetable's unique nutritional benefits and flavor profile best suit your individual dietary needs.

For additional nutritional information, you can consult the USDA FoodData Central database.

Frequently Asked Questions

No, they are different species of plants. True yams have rough, bark-like skin and starchy flesh, while sweet potatoes have smoother skin and sweeter flesh. In the U.S., many vegetables labeled 'yam' are actually a type of sweet potato.

Cooking methods like baking or boiling do not significantly reduce the fiber content itself, but they can alter the overall nutritional density. The fiber-per-gram ratio remains largely consistent.

Yams have a higher content of resistant starch compared to sweet potatoes. This type of starch functions like soluble fiber, feeding beneficial gut bacteria and supporting digestive health.

Both can be part of a healthy diet for diabetics. Yams are higher in resistant starch and fiber, which helps regulate blood sugar. Sweet potatoes generally have a lower glycemic index when boiled, releasing carbohydrates more slowly.

The vibrant orange color of sweet potatoes comes from a high concentration of beta-carotene, which the body converts into Vitamin A. True yams lack this specific nutrient in high amounts.

It depends on the recipe. Due to their distinct taste and texture, a sweet potato's sweetness might be too overpowering for a savory yam dish. The starchy, less sweet nature of a true yam makes it more suitable for savory preparations.

Both are suitable for weight management. Yams' higher fiber and resistant starch content can promote fullness. Sweet potatoes, however, have slightly fewer calories per 100g, which can also be beneficial for calorie-controlled diets.