For years, nutritionists and doctors have preached the benefits of a low-fat diet. We’ve been told that reducing the amount of fat we eat is the key to losing weight, managing cholesterol, and preventing health problems. But when it comes to your mental and physical health, simply “cutting the fat” just doesn’t cut it.

Research shows that, more than the total amount of fat in your diet, it’s the types of fat you eat that really matter. Bad fats increase your cholesterol and your risk of certain diseases, while good fats have the opposite effect, protecting your heart and supporting overall health. In fact, good fats—such as omega-3 fats—are absolutely essential not only to your physical health but your emotional well-being.

Good fats vs. bad fats

To understand good and bad fats, you need to know the names of the players and some information about them. There are four major types of fats:

• monounsaturated fats
• polyunsaturated fats
• saturated fats
• trans fats

Monounsaturated fats and polyunsaturated fats are known as the “good fats” because they are good for your heart, your cholesterol, and your overall health.

Saturated fats and trans fats are known as the “bad fats” because they increase your risk of disease and elevate cholesterol.

Appearance-wise, saturated fats and trans fats tend to be solid at room temperature (think of butter or traditional stick margarine), while monounsaturated and polyunsaturated fats tend to be liquid (think of olive or corn oil).