Monounsaturated Fat: Good or Bad?

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When it comes to diet and nutrition, the term “fat” is a mixed bag. Many automatically associate fats with bad nutrition, that they’re unhealthy — period. 

Well, while it is certainly true that some dietary fats do you no favors when it comes to health, it is not true for all dietary fats. In fact, some fats are essential.  

But what about monounsaturated fats? How do they stack up when it comes to health — good or bad? Let’s find out. 

A Quick Look at Dietary Fat

Contrary to some popular belief, fats are pretty important when it comes to our diet — but some are healthier than others. 

Fat is considered an essential macronutrient, along with carbohydrates and protein. While fat tends to be a loaded term, dietary fats are actually quite important for our health. 

For example, fats can:

  • Provide us with a source of energy.
  • Help us absorb vitamins, such as vitamins A, E, D, K (fat-soluble vitamins).
  • Helps protect and insulate our bodies and organs. 
  • Provide us with essential fatty acids, which our bodies can’t make on their own. 

Fats tend to be thought of as “bad” because they can be associated with things like high cholesterol. This is why it is important to understand that there are different types of fat, each derived from different sources and each having different roles in terms of health. 

Different Types of Dietary Fats

We can find four major dietary fats in the food we consume: Saturated fats, trans fats, polyunsaturated fats, and monounsaturated fats. Dietary fats differ when it comes to physical properties and chemical structure.

Saturated Fats

Sometimes called “solid fats,” because they stay solid at room temperature, saturated fats are found in animal-based foods and tropical fats. Examples of saturated fats include beef, lamb, pork, cheese, butter or margarine, shortening, and coconut.  

Trans Fats

Trans fats can be naturally-occurring (e.g., milk and some meats) and artificial. Artificial trans fats, like hydrogenated vegetable oils, are created and processed through industrial means in which hydrogen is added to liquid oils to make them more stable and solid. 

Polyunsaturated Fats

Chemically, polyunsaturated fats are simply fat molecules that contain more than one unsaturated carbon bond (e.g., poly, which means “many”). These belong to the class known as unsaturated fats, along with monounsaturated fats.

Monounsaturated Fats

Monounsaturated fats, or monounsaturated fatty acids (MUFAs), belong to the group of unsaturated fats. These types of fats are typically liquid at room temperature. 

Unsaturated fats also differ from saturated fats at the molecular level. For instance, saturated fats have no double bonds in their chemical structures. Instead, they are saturated with hydrogen atoms. 

Unsaturated fats have at least one double bond in the chain of fatty acids. While polyunsaturated fats have multiple double bonds, MUFAs only have one (e.g., mono, meaning one). 

Monounsaturated Fats in Diet

Monounsaturated fats are found primarily in plant sources. The most popular dietary source of monounsaturated fats is cooking oils

Here are some examples of foods high in monounsaturated fats:

  • Olive oil, safflower oil, sunflower oil, and coconut oil
  • Peanut oil 
  • Sesame oil 
  • Soybean oil
  • Palm oil
  • Canola oil
  • Avocados
  • Pistachios
  • Cashews and walnuts
  • Peanuts and peanut butter 
  • Almonds and almond butter
  • Flaxseed, which is also high in omega-3 fats
  • Salad dressings

Monounsaturated Fats: Friend or Foe?

So, where do monounsaturated fats fall in the discussion of dietary fats? Are they friends or foes? Good or bad?

There is good news: Monounsaturated fats are considered good fats, or better yet, healthy fats. In fact, unsaturated fats are typically the preferred choice over saturated and trans fats by most dietary experts. 

Many monounsaturated fats, like nuts, salmon, sardines, and other oily fish, are also high in omega-3 fatty acids, which have a variety of potential health benefits.

According to the American Heart Association, monounsaturated fats can help reduce bad cholesterol levels in the blood, lowering the overall risk for heart disease.

Monounsaturated Fats and Heart Health

High levels of low-density lipoprotein (LDL) cholesterol, often referred to as “bad” cholesterol, can lead to weight gain and may increase your risk of heart disease and stroke.

LDL cholesterol can create plaque buildup on your blood vessel walls; over time, this plaque buildup makes your vessels narrow and restricts blood flow. 

Numerous studies have found benefits in replacing saturated fats with monounsaturated fats to help lower LDL cholesterol. 

One study found a five percent reduction in LDL cholesterol among participants getting a high-MUFA diet over three months. The study compared this to a four percent LDL increase in those on a high-saturated fat diet. 

Monounsaturated Fats and Metabolic Health

High-monounsaturated fat intake has also been shown to help improve insulin sensitivity. As a hormone, insulin helps control and regulate blood sugar levels. Proper insulin production is essential for preventing metabolic disorders like Type 2 diabetes. 

One study found that substituting dietary saturated fats for monounsaturated fats helped improve insulin sensitivity in healthy adults. The study was conducted over 12 weeks. 

How Much MUFAs Should You Be Getting?

Making MUFAs your dietary fat of choice is a good first step. But how much? All fats are already calorically-rich, with twice as many calories per gram as protein and carbohydrates (9 calories per gram). 

The USDA’s Dietary Guidelines for Americans (2020-2025) do not recommend a specific intake of monounsaturated fats. However, here are their guidelines regarding dietary fats:

  • Adults should get roughly 20% to 35% of their daily calories from fats. This includes unsaturated fats like MUFAs.
  • Less than 10% of daily calories should come from saturated fats. This includes trans fats, both naturally-occurring and artificial. 


Dietary fats get a bad rap in the conversation surrounding health. But, not all fats are equal, and not all fats are “bad” — some are essential. 

Like monounsaturated fats, unsaturated fats can be found in many plant sources, most notably in cooking oils like olive oil. 

Research has shown that these fats may actually have benefits related to the heart and metabolic health. At the end of the day, when you choose your fats, choose wisely. 


Types of Fat | The Nutrition Source | Harvard TH Chan School of Public Health

Monounsaturated Fat |

Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study | NIH

Insulin resistance determines a differential response to changes in dietary fat modification on metabolic syndrome risk factors: the LIPGENE study | NIH

Dietary Guidelines for Americans 2020 - 2025 |

Healthy Directions Staff Editor