Following up on the popular Appetite for Life presentation by Cecilia Kwan, PhD, RD, in February, we present the first in a series of articles on popular myths about whether certain foods are good or bad to eat.

For a long time in recent decades, dietary fat has been considered to be very bad, especially for people who are trying to control their weight. The popular theory has been that eating fat would make a person fat and, therefore, all fats are bad to eat. The truth is, however, that there are various types of fat, and some are not only good for you but they are essential for your health.

Everyone needs fats. Fats give us energy so we can stay busy with our activities during the day. Fats insulate our body with a layer of adipose tissue, which keeps us warm and protects our organs. Fats are sources of the fat-soluble vitamins A, D, E and K, and eating fats helps us better absorb these vitamins. Fats also affect production and regulation of hormones that are important for appetite control, body metabolism, and reproduction. For these important functions, our body needs some fats. But not all fats are equal.

Fats can be grouped into three categories. Saturated fats are easily identifiable because they are usually solid at room temperature. These include animal foods (milk, cheese, and meat), butter, and tropical oils like coconut and palm oils. Unsaturated fats are usually liquid at room temperature and are further described as either monounsaturated or polyunsaturated. Foods such as avocado, nuts, flaxseed, canola and olive oils, and fatty fish like salmon are all rich sources of unsaturated fats. Artificial trans fats are created when liquid oils are turned into solid fats in a process called hydrogenation. The resulting trans fats are added to packaged and processed foods to increase their shelf life.

Which fats are, then, good for our body, and which ones are not as good? Saturated fats and trans fats increase the so-called bad cholesterol (the scientific term is “LDL”) in our blood, which increases the chance of heart attack and stroke. On the other hand, unsaturated fats, when included as part of a healthy diet, decrease the bad cholesterol and keep the good cholesterol (the scientific term is “HDL”) level high in the blood.

Unsaturated fats have other health benefits. For example, they may help to promote a steady weight or even weight loss for some people. The omega-3 fatty acids such as DHA, which is a type of unsaturated fats, provide many health benefits ranging from protecting against memory loss, to easing inflammation and improving mood.

Based on the evidence about dietary fats, the current dietary recommendation is to consume less than 10% of calories from saturated fats and less than 1% of calories from trans fats each day. Instead of eating foods high in these fats, eat foods high in monounsaturated and polyunsaturated fats such as avocado, fatty fish, nuts, seeds, or olives. And a final note: Do not replace the saturated fats or trans fats with refined carbohydrates such as foods and drinks high in sugar. By aiming for a diet rich in vegetables, fruits, nuts, beans, fatty fish and modest amounts of meat, you should be able to maintain a healthy balance of fats important for your health.

None of this information is intended to be a substitute for professional advice, diagnosis, or treatment. Always seek the advice of your doctor or other health professionals if you have any questions regarding a specific medical condition.

For a delicious way to incorporate healthy fats in your diet, try making this delicious Chocolate Mousse.