Ask the Doctors: Healthy fats have many benefits. How to include them in your diet.

Dear Doctors: Whenever I hear about how we’re supposed to eat better, there’s always something about “healthy fats.” What are these healthy fats, and what makes them so great?

Dear Reader: A robust body of research has revealed the wide-ranging benefits of healthy fats in the diet. These include lowering the risk of developing heart disease, improving cholesterol levels, helping with blood-sugar control and reducing inflammation.

Healthful fats also have a beneficial effect on blood pressure and have been shown to support gut health.

Fats are a type of lipid, which are molecules that do not dissolve in water. Healthy fats are lipids that, due to the specific chemical bonds that hold them together, remain liquid at room temperature — what we commonly know as unsaturated fats.

These types of fats are divided into two subcategories — monounsaturated fats and polyunsaturated fats. The distinction arises from their chemical bonds. Polyunsaturated fats offer the same benefits as monounsaturated fats and also contain health-supporting omega-3 and omega-6 fatty acids, which play important roles in brain function, skin and hair growth, bone health and metabolism.

Healthy fats are found in plant-based foods like walnuts, flax seeds, chia seeds, soybeans, avocados and olives. They are present in vegetable oils, too, such as olive, safflower, corn, sesame, canola, walnut and soybean oils.

They’re also found in fatty fish, which are an excellent source of a certain form of omega-3 fatty acid. Fatty fish, sometimes referred to as oily fish, include tuna, salmon, mackerel, whitefish, herring and sardines.

Oysters, mussels and some types of fish roe also are good sources.

A recent analysis of several large studies found that having two or more servings of fatty fish a week can help prevent cardiovascular disease in people who are at high risk.

Lovers of dark chocolate will be happy to know it contains monounsaturated fats, though only in small amounts. But dark chocolate, beside being rich in disease-fighting antioxidants, usually also contains sugar and should be eaten in moderation.

Many of us don’t get adequate amounts of healthy fats in our diets.

You can help make sure that you do by cooking with vegetable oils, limiting saturated fats, avoiding trans fats and eating at least one good source of omega-3 fats each day.

Dr. Eve Glazier and Dr. Elizabeth Ko are internists at UCLA Health.