There is hardly a more maligned nutrient in the modern diet than fat. It has gotten a bad rap since the 1960s when it was unfortunately blamed for causing heart disease, a finding that has been scientifically proven incorrect in many studies since (more on this another day). But by and large, misconceptions about fat still exist. Fat free and low fat products are still being sold in stores (which means people are still buying them) and many people are still advised by their doctors to follow a low fat diet.
Folks, I hate to break it to you but fat is 100% necessary for our bodies to be healthy. Correction, healthy fat is 100% necessary for our bodies to be healthy. There is a huge difference between the fat in a fast food meal and the fat in a cut of grass fed steak. Unfortunately, as a population, we are consuming more of the unhealthy types of fats, hydrogenated and trans fats, and less of the healthy fats our bodies desperately need to function. (Do yourself and your body a favor and avoid hydrogenated and trans fats at all costs).
Fat composes about 15% of our body weight and performs numerous functions. Fat is a source of energy for the body, a primary building block of the membrane surrounding all of our cells and of hormones, it’s presence is necessary for the absorption of fat soluble vitamins (A, D, E, and K), it allows for the proper use of proteins in the body, provides a protective lining for the organs of the body, regulates energy absorption by slowing the absorption of food, increases satiety, and makes food taste super yummy.
There are three main categories of fats, named according to the degree of saturation of the chains of carbon atoms that make up the structure of the fatty acid molecule. All healthy fats found in nature are a combination of all three types.
Saturated Fats: Highly stable, saturated fats do not go rancid easily, are solid or semi-solid at room temperature, and are found in animal fats and tropical oils such as coconut and palm oil. These oils are ideal for cooking at high temperatures.
Monounsaturated Fats: Relatively stable, monounsaturated fats don’t go rancid easily, are liquid at room temperature, and are found in olive oil and oils from almonds, pecans, cashews, and avocados. These oils can be used for low temperature cooking.
Polyunsaturated Fats: Relatively unstable, polyunsaturated fats go rancid easily, are always liquid, should never be heated or used in cooking, and are found in flax, nuts, seeds, and fish oils. These oils are ideally consumed raw.
A quick note on the stability of polyunsaturated fat, which is the fat primarily found in corn, safflower, and peanut oils. This type of fat is quite unstable and is easily prone to rancidity through heat, light, and oxygen. Therefore, it is important that these oils are never used in cooking, which will damage their structure and cause them to be inflammatory to the body when consumed. Also look to purchase these oils in dark containers, which protect the oil from exposure to light in shipping.
There are two fats that are essential to the body, meaning we cannot make them ourselves and must get them from our food. These are linoleic acid (commonly known as omega-6) and alpha-linolenic acid (commonly known as omega-3). All other fats can be derived from these two essential fatty acids. Omega-3 and omega-6 fatty acids are polyunsaturated fats. Examples of omega-6 fatty acids include corn, safflower, and peanut oils. Examples of omega-3 fats include flax, wheat germ, walnut, hemp, and fish oils from fatty cold water fish such as salmon. Ideally, we should be eating as many omega-3 fats as omega-6 in our diets, though most Americans eating a processed food diet get way more omega-6 fats.
Healthy fatty acid deficiency is epidemic. Not getting enough healthy fats in the diet causes musculoskeletal issues, endocrine issues, cardiovascular issues, immune issues, allergies, skin problems, and depression. So don’t be scared of healthy fat! Aim on eating a balance of all three types of the healthy fats above, prepared properly, and from good quality sources.