Nutrition / Food

Types of Fats: What to Eat and What to Avoid

A registered dietitian weighs in.

Fats have a bad rep. If we want to lose fat, shouldn’t we avoid eating it? Fortunately, it’s not that simple. With the help of science and a rise in popularity of certain diets, such as the Mediterranean diet, this narrative is changing.

Yes, we have fat in our body (and it’s necessary that we do, by the way!). No, eating an avocado or handful of nuts won’t automatically pack on the pounds.

In fact, in some cases, those healthy fats may actually help you reach your weight loss goals along with the Aaptiv audio-fitness app. Fats help us feel satisfied, absorb certain vitamins, and support optimal heart, brain, and nerve function.

But not all fats are created equal, so we spoke with registered dietitian Carrie Dennett, M.P.H., R.D.N., C.D., and owner of Nutrition by Carrie, to set the record straight.

Read on to see what we found out about the different types of fats and why they’re important.

What makes a fat healthy or unhealthy?

“Research by the California Walnut Commission found that 81 percent of people know there are ‘good’ and ‘bad’ dietary fats, but only 19 percent know which fats are good and bad,” Dennett pointed out.

So, which of the fats are good and bad? To put it simply, trans and saturated fats are proven to be harmful to your heart in large quantities. Obviously, that’s bad, so think of these as the bad fats. On the other hand, monounsaturated and polyunsaturated fats have proved beneficial to heart health. So, these are the good fats.

It’s never that simple, though, right? Here’s a deeper look into the types of fats:

Trans fat: Short for trans-fatty acids, these are the least healthy fats. They come from an industrial food process that adds hydrogen to vegetable oils to make them solid. Trans fats are listed as partially hydrogenated oils, so look out for that name on your ingredient labels. This fat is common in doughnuts, cookies, cakes, margarine, fried fast foods, and microwavable meals.

Saturated fat: Typically linked with high cholesterol and an increased level of low-density lipoprotein (LDL), these fats may increase your risk of heart disease and diabetes. Find these in meat, such as beef, pork, lamb, dark chicken, and dairy, such as milk, butter, cheese, ice cream, as well as tropical oil products, such as coconut oil, cocoa butter, and lard.

Monounsaturated fat: Also called oleic acid, these fats are healthy and helpful. Opposite to saturated, they can reduce inflammation and aid in lowering cholesterol levels. Find them in avocados, olives, olive oil, vegetable oils, most tree nuts, and nut butters.

Polyunsaturated fat: Just like monounsaturated fats, they can lower your cholesterol level and your risk for heart disease. Omega-3 fatty acids are a popular type of polyunsaturated fat that boast disease-fighting and blood pressure–lowering benefits. Find polyunsaturated fats  in tofu, walnuts, seeds, vegetable oils, and soy beans. Omega-3s are present in fish (salmon and sardines), flaxseeds, chia seeds, walnuts, and canola oil.

How much fat should I eat?

While official dietary recommendations no longer suggest a total fat limit, Dennett recommends limiting saturated fat to ten percent of your total daily calories.

Replace Saturated with Monounsaturated and Polyunsaturated

“When reducing saturated fat, it’s important to consider what you’re replacing it with,” Dennett says. “Replacing it with refined carbohydrates—which is what happened during the ‘low-fat era’—is not good for health. However, swapping saturated fats for healthy polyunsaturated or monounsaturated fats has real health benefits.”

Note that she mentioned refined carbs, not all carbs. Carbohydrates are extremely good for the body when they’re the right ones. As mentioned above, switching out saturated for monounsaturated or polyunsaturated will have a positive effect on your cholesterol and blood pressure. It may even go as far as preventing cardiovascular disease and stroke.

A study from the American College of Cardiology, found that people who regularly eat nuts have a lower risk of developing heart disease than those who rarely, if ever, eat nuts. “That’s likely because of both the polyunsaturated and monounsaturated fats they contain,” she says.

Include Omega-3s

Omega-3s are a much-talked-about nutrient for a reason. When eaten in large quantities, they aid eyesight and heart health, and help alleviate they can aid in stiffness, joint pain, depression, and anxiety.

“The omega-3 fats found in fish—EPA and DHA—have established benefits for brain and heart health, in part due to their anti-inflammatory benefits,” Dennett says. “Plant-based omega-3s found in walnuts, flax seeds, and chia seeds don’t have the exact same benefits, but they have their own unique benefits. Walnuts are one of my top picks for an anti-inflammatory diet.”

The Takeaway

Thankfully, fats aren’t nearly as demonized as they used to be. The rise of the Mediterranean diet largely plays into this, promoting heart healthy, satisfying foods.

“With their high levels of both polyunsaturated and monounsaturated fats, and relatively low levels of saturated fats, it’s no surprise that traditional Mediterranean diets are so good for the heart, brain, and the rest of our bodies,” says Dennett.

Everything considered, monounsaturated and polyunsaturated fats can have amazing effects on the body. Just be sure to limit your intake of trans and saturated fats (although a treat here or there won’t hurt anybody).

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