Monounsaturated fats, such as olive oil, are a healthy addition to the diet. They can aid in heart health and diabetes. However, they should be consumed in moderation.

Unlike saturated fats, which can have negative health effects, monounsaturated fats may support heart health and help someone manage their weight. However, all fats are calorie-dense, and people may put on weight if they eat them excessively.

This article explains what monounsaturated fat is and how it compares to other types of fat. It looks at potential health benefits, how much to eat, and food sources.

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Monounsaturated fat is present in both plant foods and animal products. One of the healthiest examples of monounsaturated fat that people may be familiar with is olive oil.

Chemically speaking, monounsaturated fatty acids (MUFAs) are fat molecules with one unsaturated double carbon bond. These fats are usually liquid when at room temperature and turn solid when chilled.

In common with all types of fats, monounsaturated fats contain nine calories per gram.

According to the American Heart Association (AHA), monounsaturated fats can positively affect someone’s health when they eat them in moderation.

The AHA advises that the majority of fats that people eat should be monounsaturated or polyunsaturated fats.

People should consume monounsaturated or polyunsaturated fats instead of foods that contain saturated or trans fats, as these can negatively affect their health.

The following sections look at what the evidence says about specific health effects of monounsaturated fats.

Heart health

Some evidence suggests that monounsaturated fats can improve heart health.

For example, the PREDIMED study indicated a link between intakes of MUFAs and polyunsaturated fatty acids (PUFAs) and a lower risk of cardiovascular disease.

The AHA also advises that monounsaturated fats can improve someone’s cholesterol profile and lower their risk for heart disease and stroke. They add that monounsaturated fats also contribute the antioxidant vitamin E to the diet, which many people living in the United States are deficient in.

A 2018 review explains that compared to eating a high saturated fat meal, consuming a high monounsaturated fat meal has the following benefits:

  • larger, more buoyant low-density lipoprotein (LDL) particles, which are less dangerous to heart health
  • faster clearance of fats after eating
  • more fat burning and less fat storage
  • reduction in fasting triglycerides and coagulation factors

Additionally, a 2019 laboratory study on human veins showed that MUFAs prevented the damaging effects of saturated fats on cells.

Although scientists need to do more research, the researchers suggest that the protective effects of MUFAs could be important for heart health.


According to a 2016 systematic review and meta-analysis, diets high in MUFAs may benefit people with type 2 diabetes.

The review suggested that compared to high carbohydrate diets, high MUFA diets reduced the following risk factors:

  • fasting plasma glucose
  • triglycerides
  • body weight
  • systolic blood pressure

The researchers also found that high MUFA diets increased beneficial high-density lipoprotein (HDL) cholesterol.

Additionally, high MUFA diets had more beneficial effects on fasting glucose than high polyunsaturated fatty acid diets.

Inflammation and obesity

According to a 2021 review, evidence links MUFAs to anti-inflammatory states and less obesity. Conversely, saturated fats are inflammatory and can contribute to excess weight and obesity.

The researchers point out that the Mediterranean diet includes 60% MUFAs compared with 36% in the Western diet.

People consuming a Mediterranean diet have less incidence of obesity and its related inflammatory effects, such as cardiovascular disease.

Furthermore, the TOMORROW study suggested that anti-inflammatory MUFAs might suppress disease activity in patients with rheumatoid arthritis.

There are no government guidelines for how much monounsaturated fat to eat. However, the AHA advises that people should replace saturated and trans fats with MUFAs and PUFAs.

With nine calories per gram, fats are more energy-dense than carbohydrates and protein, which provide four calories per gram.

Consuming too many calories can lead to weight gain, so people should be mindful of the amount of fats they eat.

Although animal products such as eggs and meat contain MUFAs, the richest sources are plant foods. Good sources of MUFAs include:

  • olive oil
  • canola oil
  • peanut oil
  • sesame oil
  • safflower oil
  • avocados
  • peanut butter
  • nuts and seeds

Monounsaturated fats are a healthy addition to a person’s diet.

Compared to saturated fats, which experts advise that people limit, monounsaturated fats can have several health benefits. These include less risk of obesity and heart diseases.

A sensible approach is to replace most saturated fats with monounsaturated or polyunsaturated fats. However, to maintain a moderate weight, people should not eat too much fat.