Why Are Fried Foods So Bad for You?

A side of salty French fries with your entrée at dinner. A crispy funnel cake from the street festival you attend with your family. A juicy fried chicken sandwich from the fast food joint next door to your office.

If you’re feeling tempted, you’re not alone. Fried foods are everywhere, and there’s no denying it: They taste delicious. But there’s no denying this either: They also bring health risks.

What’s unhealthy about fried foods?

We hate to say it, but the better question might be: What’s not unhealthy about fried foods? Though they may be tasty, they also:

• Are high in calories
• Are sometimes high in trans fats
• Cause inflammation and oxidative stress in your body
• Negatively affect your gut health
• Raise your risk of conditions like obesity and heart disease

And that’s just a highlight reel. Registered dietitian Devon Peart, RD, MHSc, BASc, delves deeper into these and other health risks of fried foods.

They’re high in calories

OK, be honest: Have you ever eaten fried zucchini sticks and thought, “There’s a vegetable in there! How unhealthy can it be?” Unfortunately, the answer is still: pretty bad. As you add batter, flour and oil, the calories start to stack up.

“Frying affects foods that may otherwise be healthy by adding extra calories,” Peart explains. “Fat is more than twice as high in calories compared to carbs and protein, so foods that are fried in oil (which is a fat) are higher in calories.”

In other words, when a food is fried, it absorbs some of the oil, adding fat and becoming much higher in calories than it would’ve been without it.

Let’s keep using those zucchini sticks as an example. A regular stick of zucchini — the real thing, grown in a garden — is just 30 calories. But the type of deep-fried zucchini sticks you might order in a restaurant run anywhere from 200 to 300 calories per order … and that’s not including whatever dip you dunk them in and whatever beverage you wash them down with!

They’re full of trans fats

Fried foods are a source of trans fats, a type of fat known to increase your risk of heart disease. They raise your LDL cholesterol (the “bad” kind) and decrease your HDL cholesterol (the “good” kind).

Trans fats are naturally present in small amounts in some foods, like milk and meats. But they’re also made during the food manufacturing process. Trans fats are formed when hydrogen is added to vegetable oil to make it more solid (“partially hydrogenated”).

That partially hydrogenated oil is found in vegetable shortening and is used in commercially baked and fried foods like French fries, donuts, hard-stick margarine and snack foods. Partially hydrogenated oil is also used in the restaurant industry.

“Using this type of oil in restaurant fryers allows the same oil to be used over and over again throughout the day,” Peart says, “so it’s quicker and cheaper, but definitely not good for you!”

In Canada and the U.S., food manufacturers aren’t allowed to add partially hydrogenated oils to packaged food in a significant amount — but they can still add it in small amounts, which can add up.

Another type of fat that can cause health issues is saturated fat, which is solid at room temperature. Bacon fat, red meat and coconut oil are all sources of saturated fat.

“Saturated fats are less bad for you than trans fats, but they still raise cholesterol,” Peart cautions. “Current research is conflicting in terms of whether saturated fat raises heart disease risk, but studies show that replacing saturated fat with healthier (unsaturated) fat and/or high-fiber carbs reduces the risk of heart disease.”

They contribute to obesity and overweight

“High-calorie foods can make it difficult to maintain a healthy weight and can lead to obesity, which is a risk factor for health,” Peart states. And fried foods aren’t just high in calories. They’re also often packed with sodium (salt), all of which can contribute to having overweight — especially if you eat fried foods regularly. 

A high-fat diet has also been shown to lead to insulin resistance, which is a risk factor for obesity and Type 2 diabetes.

They cause oxidative stress

Fried foods are considered “pro-oxidative,” which means they lead to oxidative stress in your body. We hear you thinking: “Stress?! I’ve never felt stressed while eating mozzarella sticks!” But oxidative stress isn’t that kind of stress.

At high temperatures, fats and oils go through a process called oxidation, which creates free radicals — unstable atoms that can wreak havoc on your health.

“Oxidative stress can damage your cells and make it harder for your immune system to fight off illness and infection,” Peart explains. It’s also associated with the development of conditions like cancer and heart disease.

They negatively affect your gut health

That eggplant parmesan seemed like a great idea at the time, but you’re likely to rethink the decision a few hours later, when you’re feeling rumbly and bloated — or worse.

The fats and oils used to cook fried foods are harder for our body to digest, which can cause digestive woes like gas, stomach pain and diarrhea. And that’s just in the short term.

“High-fat diets can promote the growth of harmful bacteria in the gut,” Peart warns. “They can also cause a lack of ‘good’ bacteria and lack of microbial diversity — meaning there’s not enough variety of the good stuff.”

They lead to inflammation

You’re probably familiar with inflammation as it relates to, say, a cut on your finger that’s healing. But chronic inflammation inside your body can cause symptoms like pain, fatigue and a weakened immune system. Over time, it can contribute to other health conditions, too.

The foods you eat (or avoid) can play a big role in that inflammation. Some foods (think whole foods like fruits, veggies and lean proteins) fight and prevent inflammation. Others, like ultra-processed foods and (you guessed it!) fried foods, can contribute to inflammation.

“Fried foods can cause the immune system to release pro-inflammatory cytokines proteins that trigger an immune response,” Peart shares. “Too many cytokines lead to excess inflammation.”

They raise your risk of heart disease

“Depending on the type of fat they’re fried in, fried foods can lead to an increased risk of heart disease,” Peart says. “That’s especially important to know because in the U.S. and Canada, cardiovascular disease is the leading cause of death.”

Studies show that diets high in saturated fat can raise LDL cholesterol and lower HDL cholesterol, increasing your risk of heart disease. That includes conditions like:

• Heart attack
• Coronary artery disease
• Stroke

One review found that people who ate the most fried foods each week were 28% more likely to develop heart problems than those who ate the least amount.

They can cause reflux

Fat is satiating, which means it makes you feel full. This can be a good thing, but…

“Fat is also a common trigger for reflux, or what we typically refer to as heartburn,” Peart explains. “Reflux happens when stomach acid from digesting food makes its way back up your esophagus.”

This can be uncomfortable and even painful. It might make you burp or cause an unpleasant, sour taste in your mouth. And lying down can make reflux worse, so you may be more likely to get it if you eat fried food too close to bedtime (or if you order fast food takeout and then burrow into the couch to watch a movie).

They may include acrylamide

Methods of cooking that use high heat, like frying, can create a chemical called acrylamide to form in plant-based foods like grains and potatoes. (Potatoes, of course, lend themselves to lots of frying possibilities.)

Though more research is still needed to figure out how acrylamide affects humans, lab studies show that in high doses, it may lead to cancer. But trying to avoid acrylamide shouldn’t definitively rank on your list of reasons to avoid or minimize fried foods — the rest of the list is long enough!

Are there any healthy alternatives to frying food?

You don’t necessarily have to cut fried foods out of your diet altogether or forever. But being choosy about which ones you eat and how often will help lessen their effects.

• Nix deep-fried foods. All fried foods have potential negative health effects, though not to the same extent. “The more a food is submerged in oil, the more fat it absorbs,” Peart says, “so deep-frying leads to more fat consumption and more calories.” Deep-frying is also done at higher temperatures, which creates cancer-causing substances called carcinogens.
• Go for pan-frying in moderation. Pan-frying is a cooking method done at lower temperatures than deep-frying, and it generally uses less oil, too. Though it’s healthier than deep-frying, it’s still not as healthy as cooking methods like air-frying or baking. “If you pan fry, try using olive oil for low temperatures or avocado oil for higher temperatures,” Peart suggests. “These fats are still high calorie, but they’re heart-healthy fats.”
• Embrace air-frying. For your French fry and chicken wing needs, air frying is the healthiest way to go. These handy contraptions “fry” food by circulating hot air and using much less oil, translating to far fewer calories and less fat. “I drizzle or brush food with olive oil and use herbs like crushed black pepper and paprika,” Peart shares.
• Beware any foods you haven’t fried yourself. “In food service, the oils used are generally cheaper ones that are more saturated and less healthy,” Peart warns. (We’re looking at you, county fair corndogs.)

Of course, there are lots of other methods of cooking, too. In addition to adding air-frying to your repertoire, you’re best sticking to techniques like roasting, grilling, baking, sautéing or stir-frying, which typically use less fat. And keep an eye on your ingredients: Go heart-healthy by swapping in olive oil for butter and using herbs in place of salt.

A final word about fried foods and other fats

Fried foods are loaded with calories, saturated fats and trans fats, making them risky for your overall health. But it’s important to remember that not all fat is bad. In fact, your diet needs some fats!

“Unsaturated fats are beneficial for cholesterol and heart health,” Peart clarifies. “Heart-healthy fats are typically those associated with the Mediterranean diet.” They include:

• Avocados and avocado oil
• Nuts
• Seeds
• Olive oil
• Omega-3 fatty acids, found mainly in fatty fish (like salmon, trout and mackerel)

Still, even healthy fats are high in calories, so pay attention to how much you eat, especially if you’re managing your weight.

“My advice is to avoid trans fats, limit saturated fats, eat home-prepared foods most often and only eat fried foods occasionally,” Peart says. “Enjoy a moderate amount of healthy fat daily: a handful of nuts, a third an avocado or some fresh olive oil with balsamic vinegar in your salad.”