Saturated vs. unsaturated fat: Why nutritionists say unsaturated is healthier and how to get more in your diet

• Unsaturated fats are healthier than saturated fats because they help lower cholesterol and improve heart health, whereas saturated fats can increase cholesterol.
• Both saturated and unsaturated fats can be a part of a healthy diet, though it's important to consume them in moderation.
• For a healthier diet, you should try swapping out saturated fats like butter and red meat for unsaturated alternatives like olive oil and salmon.
• This article was medically reviewed by Samantha Cassetty, MS, RD, nutrition and wellness expert with a private practice based in New York City.

Fat is an essential part of a healthy diet. It helps our bodies absorb vitamins and minerals, maintains metabolism, and stores energy. But not all dietary fats are created equal.

Here is what you need to know about the differences between saturated and unsaturated fats, their effects on your health, and how much of each you should be eating.

What is saturated fat?

Saturated fats are fat molecules with only a single bond between carbon molecules. They are found in animal products and tropical oils like coconut and palm oils, says Alana Kessler, a registered dietitian and nutrition consultant based in New York City.

Saturated fats are typically solid at room temperature and include:

• Fatty pieces of red meat like lamb or beef
• Full-fat dairy products, such as whole milk, butter, cream, and cheese
• Coconut oil

Eating too many saturated fats can raise low-density lipoprotein (LDL) levels — the "bad" kind of cholesterol that increases your risk of heart disease.

What is unsaturated fat?

Unsaturated fats are fats with one or more unsaturated carbon bonds, Kessler says. Unlike saturated fats, which are solid at room temperature, unsaturated fats are liquid at room temperature and harden when chilled.

There are two types of unsaturated fat. They are:

• Monounsaturated fats: These help lower LDL cholesterol levels, which reduces the risk of heart disease. Monounsaturated fats also provide our body with vitamin E, an essential vitamin.
• Polyunsaturated fats: These also lower LDL cholesterol levels and provide you with vitamin E. Polyunsaturated fats provide essential fats your body can't produce itself like omega-3s, which are tied to health benefits, such as reducing inflammation in the body.

Unsaturated fats are mostly found in foods from plants and seafood, including:

• Olives and olive oil
• Vegetable oils, like canola and sunflower
• Fatty fish like salmon and mackerel
• Nuts and seeds like almonds and flax seeds
• Avocados

Is saturated or unsaturated fat healthier?

In moderation, both fats can have benefits, and in excess, both fats can be counterproductive to your overall health, Kessler says. In general, unsaturated fats are healthier and can help lower inflammation and positively impact cholesterol.

On the other hand, saturated fats raise levels of blood lipids. These fatty substances found in the blood, such as cholesterol and triglycerides, may be associated with poor cardiovascular health. But the science is less clear on whether or not there is a direct correlation between high blood lipid levels and heart disease.

For example, a 2014 review involving more than 650,000 participants found no association between saturated fat intake and heart disease. But other studies do show a link. A 2020 analysis with more than 56,000 participants concluded that cutting down on saturated fat resulted in a 17% reduction in the risk of cardiovascular disease.

While research on saturated fats is still emerging, there is strong evidence that unsaturated fats have a positive effect on heart health.

A very large 2009 study found that participants who replaced 5% of their dietary intake of saturated fats with polyunsaturated fats were significantly less likely to experience coronary heart disease than those who did not over a four to ten year follow up period. The study also found that swapping 5% of saturated fats with monounsaturated fats or carbohydrates did not reduce coronary heart disease risk.

Another smaller study on overweight and obese people found monounsaturated fats decreased their risk of cardiovascular disease by lowering LDL cholesterol levels.

Unsaturated fat appears to offer more health benefits than saturated fat, but it's important to remember that dietary fat is one part of your overall diet and lifestyle. Maintaining healthy habits like exercising regularly, not smoking, and consuming a variety of wholesome foods, including vegetables, fruit, and whole grains can all reduce your risk of heart disease.

Recommendations for fat intake

Fat is an essential part of our diet.

"Fat is one of the three key macronutrients that we need for our health," says Eshani Ewing, a registered dietitian with Orlando Health, a not-for-profit healthcare organization.

Overall, the American Academy of Nutrition and Dietetics recommends unsaturated fats make up 20% to 35% of your total daily calories, and saturated fats make up less than 10%. The American Heart Association recommends limiting saturated fat even more to less than 6% of your daily calories.

It can be especially helpful to replace saturated fats with unsaturated fats in your diet. Some easy ways to swap out saturated fats for their unsaturated counterparts include:

• Cooking with olive oil instead of butter
• Using vinaigrette dressings instead of ranch
• Eating nuts or seeds as snacks instead of cheese or pastries
• Consuming salmon instead of red meats like steak

While both saturated and unsaturated fats can be part of a nutritious diet, trans fat — a third type of fat — should be avoided. Trans fats offer no nutritional value and can increase your risk of heart disease and stroke.

Trans fats can be found in fried and processed foods like:

• Frozen pizza
• French fries
• Donuts

It's important to note that, as of 2018, most food processors have stopped using trans fats due to FDA regulations.

The bottom line

Fat is an important part of a healthy diet, but not all fats are equally beneficial. For a nutritious diet, avoid trans fat as much as possible, eat saturated fat in moderation, and try to boost your consumption of foods high in unsaturated fat, like avocados and salmon.

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