When you're trying to eat healthy but also really want to order that greasy cheeseburger, nothing vindicates your decision more than opting to sub regular french fries for sweet potato fries. Sure, your burger may be a little unhealthy — but at least you made the healthier choice when it came to your side.

Or did you?

"Sweet potato fries are often thought of as a healthier alternative to regular french fries. And while sweet potatoes themselves can come with a few extra health benefits, this is subject to change based on how they're prepared and cooked," says Emma Willingham, clinical dietitian at Houston Methodist.

If you order sweet potato fries knowing they're just as unhealthy as regular fries, carry on. But if you order them because you think they're a healthier option, we recommend you read on.

Sweet potato vs. white potato — which is healthier?

The reason regular french fries probably get a bad rap is that they're deep-fried, often paired with high-calorie choices (aka, that greasy burger), and many of us overeat this tasty side.

"Studies on french-fry consumption show that regular french-fry intake is linked to weight gain, obesity and food addiction in both adults and children — so it's no surprise that we perceive them as an unhealthy choice," says Willingham.

But are sweet potato fries really any different? They're also deep-fried, paired with burgers and served in heaps.

"These same types of studies haven't been carried out for sweet potato fries, specifically. What we do know, however, is that — before any cooking happens — both white potatoes and sweet potatoes are nutritious. And almost equally nutritious at that," adds Willingham.

Raw sweet potatoes and white potatoes have comparable nutrition profiles, with similar calories per serving and macronutrient breakdown.

Sweet potato nutrition (about 1/2 cup, raw)

• Calories: 86 calories
• Carbs: 20 g.
• Fat: 0.05 g.
• Protein: 1.6 g.
• Fiber: 3 g.
  
  

White potato nutrition (about 1/2 cup, raw)

• Calories: 69 calories
• Carbs: 15.7 g.
• Fat: 0.1 g.
• Protein: 1.7 g.
• Fiber: 2.4 g.
  
  

There are some differences between these two potato types, though.

While both are root vegetables, they belong to different plant families. Sweet potatoes fall into the morning glory family, while regular potatoes are nightshades. And they have different micronutrient breakdowns because of this.

"For instance, raw sweet potato contains 100 times more Vitamin A — a nutrient important for vision — than regular white potato. Sweet potato is also higher in potassium, which can help restore electrolyte imbalance and prevent muscle cramping and soreness," explains Willingham.

In addition, sweet potato, depending on how it's prepared, can also have a lower glycemic index than white potato. The lower the glycemic index, the more gradually the food will raise your blood sugar.

"If you have prediabetes or diabetes, choosing sweet potato over white potato can help reduce your chance of a blood sugar spike," adds Willingham. "Just be aware that this only holds true if you're boiling or air frying the sweet potato. Once fried or baked, the glycemic index of sweet potato becomes similar to that of a french fry."

So, does it matter which type of fry you choose?

This likely isn't new information, especially when it comes to deep frying, but the way we cook our food can change its nutrient breakdown and health benefits.

"Deep frying always makes food unhealthy. Submerging food in cooking oil increases the calories, carbs and fat content. In addition, if the frying oil is being used over and over, trans fats can be created and seep into the food," adds Willingham. "What's more is that deep frying may also increase the amount of carcinogens in the food. However, more research is needed to confirm this."

And this is true for any type of fry.

"With very similar nutrient profiles and the fact that deep frying either type of potato essentially makes both equally unhealthy, there's no real health benefit to choosing sweet potato fries over regular ones," adds Willingham.

And one last FYI — whether sweet or regular, fries are often served in portion sizes that contain as many calories as needed for an entire meal.

For healthier regular or sweet potato fries, opt for air frying

Baking potatoes, instead of deep frying them, may seem like the healthier alternative, but Willingham says there's one that's even healthier: Air frying.

Air fryers use super-heated air to quickly cook foods.

"Air frying is a great way to make sweet potato fries or regular french fries without using excessive amounts of oil. Even just 1 tablespoon of olive oil is all you need to make crispy fries in an air fryer," says Willingham. "The added benefit of air frying sweet potato fries, instead of baking or deep frying them, is that it keeps the glycemic index lower, making a blood sugar spike less likely."

But whether you're eating deep-fried, baked or air-fried fries, know that it's okay if your choice between sweet potato or regular simply comes down to personal preference.

"At the end of the day, the nutrition composition of the two is so similar that I recommend eating the type of potato you enjoy most. If your regular or sweet potato fries are deep-fried, keep an eye on the portion size. If you're making fries at home, opt for air frying as your cooking method, and you may benefit from choosing sweet potatoes if you're in need of some extra vitamin A and potassium and/or are keeping an eye on your blood sugar," adds Willingham.