Sweet Potato Fries vs. French Fries: Which Is Healthier?

Sweet potato fries have a reputation for being healthier than French fries, but you may wonder whether they’re really better for you.
After all, both kinds are usually deep-fried and served in oversized portions.
This article reviews the nutrition of sweet potato and French fries, as well as their potential health effects.
Nutrition Comparison
Detailed nutrition information is most readily available for store-bought, frozen fries.
The following nutritional comparison is for a 3-ounce (85-gram) serving — or 10–12 pieces of frozen fries — which can be baked as-is from the freezer:

*Fat and sodium content may vary between different brands of either type of fries.
Sweet potato fries are slightly higher in calories and carbs but also more nutrient dense than French fries.
The greatest nutrient difference is that French fries have no vitamin A, while sweet potato fries are high in this nutrient. Vitamin A is important for your vision and immune system.
SUMMARY: Sweet potato fries are a bit higher in calories and carbs than French fries.
However, sweet potato fries are also more nutrient dense and particularly high in vitamin A.
Serving Size and Cooking Methods Matter
The table in the previous chapter shows that a 3-ounce (85-gram) serving of baked French fries has 125 calories, compared to 150 calories for the same serving of baked sweet potato fries.
In contrast, fries at restaurants are typically deep-fried — which nearly doubles the calorie content.
Here’s a comparison of the average calories, fat, and carbs in different size orders of deep-fried fast food fries:

A large serving of each kind of fast food fries has as many calories as some people need in an entire meal.
Additionally, the carb and fat content are about doubled if you choose a large rather than a small serving — regardless if they’re French or sweet potato fries.
SUMMARY: Deep-frying nearly doubles the calories in both French and sweet potato fries compared to baking. When deep-fried, a large serving of either type of fries contains a full meal’s worth of calories.
Concerns Over Frying
Two issues that have made news headlines over the past few decades are trans fat and acrylamide in fries.
Is Trans Fat Still a Problem?
Trans fat in fries and other processed foods became a big concern in the 1990s, as studies linked it to increased heart disease risk.
Fortunately, new FDA rules ban the use of partially hydrogenated oil — the primary source of trans fat — in the U.S. food supply as of June 2018, though some may remain in the food supply until January 2020 as inventories are depleted.
Therefore, you should no longer see “partially hydrogenated oil” in ingredient lists of fries, nor should you find any trans fat listed in their nutrition information.
However, it’s likely still wise to limit your intake of deep-fried foods, as two studies suggest that small amounts of trans fat may form when oil is repeatedly used in a deep fryer.
Acrylamide Forms in Both Types of Fries
Acrylamide is a potentially harmful compound discovered in 2002 in cooked, starchy foods — including fries. In fact, fries are one of the major dietary sources of acrylamide.
It’s formed through a reaction between the amino acid asparagine and certain sugars when starchy foods are fried and — to a lesser extent — when they’re baked or roasted.
Though most studies on acrylamide levels in fries have tested French fries, this compound also forms in sweet potato fries and is what makes fries brown.
Acrylamide is classified as “probably carcinogenic” in humans. However, this is based on studies of animals given high doses of the compound.