Finally on our tour of the macronutrients are Fats! Another term you might be familiar with that is similar is Lipids, and the distinction is that lipid is a broader term. Kind of a square-rectangle relationship if you will. While fat has been the villain in the past, it is making its way back into popularity, but the truth is, it is just another macronutrient that should be present in a balanced eating lifestyle.
Like carbohydrate, fat contains carbon, oxygen, and hydrogen atoms, but because the fatty acid chains have more carbon and hydrogen relative to oxygen, they provide more energy per gram when compared to protein or carbohydrates – this will become important later, tuck this away for now.
Fat’s behavior in the body is related in part to the saturation of the fatty acids (i.e the amount of hydrogen it contains). Saturated fats contain all the hydrogen they can carry (no double bonds), and most animal fats and tropical oils are relatively high in saturated fatty acids. In unsaturated fats, some of the positions where hydrogen atoms are usually attached are missing, and carbon atoms are joined together by double bonds. Fatty acids containing one double bond are called monounsaturated, and olive, peanut, and canola oils are high in monounsaturated fatty acids. With two or more double bonds, a fatty acid is polyunsaturated, and soy, corn, sunflower, and safflower oils are relatively high in polyunsaturated fatty acids. An important thing to note is that no food item contains 100% of a certain type of fat. Most dietary fats and oils are a mix of all three types of fats, with one type predominating.
Fat serves many functions within the body. Energy is stored primarily as fat tissue, and while commonly considered negatively, body fat is necessary for insulation and protection of organs, and for hormonal regulation. Fat also serves as a carrier for many fat-soluble vitamins, and supplies the essential omega-6 and omega-3 fatty acids which are necessary for the formation of healthy cell membranes, the proper development and functioning of the brain and nervous system, and the production of hormones. Without fat, we would not be able to live!
Additionally, fat is responsible for the characteristic flavor, aroma, and texture of many foods, and promotes a feeling of fullness after a meal. Read: it tastes good.
But how much should I consume? That is the real question right there. Assuming you have read the previous posts on protein and carbohydrates, and assuming that you have taken the advice given within, fat should make up the rest of your diet. That was easy! But also not very clear or satisfying, right? Here’s the deal. If you are eating enough protein (by the way, most protein sources are also great fat sources), and you are eating 800 grams of fruit and vegetables each day, you probably don’t want or need to eat much more than that. It all kind of works out. Now you should monitor your fat intake as it does have a greater effect on total caloric load than protein or carbohydrates, so those looking to lose some weight will want to proceed with caution. Additionally, like carbohydrates, try to vary the fat sources you consume. The two essential fatty acids (the omega-6 and -3) need to have a rough balance. By varying your diet you can help to keep these in the desired ratio, which is roughly 1:1 to 1:4 omega-3:omega-6. Typical American diets are very high in omega-6 due to the prevalence of seed oils in today’s culture.
I will conclude with fat and its relation to performance, seeing as most of us want to optimize our performance. Fats provide more energy per gram when compared to protein or carbohydrates as I mentioned before, just over twice as much in fact. This is important because ultimately staying alive is a matter of energy production – once we can no longer produce energy, we die. Generally, fat is used for energy production in low intensity, long-term activities – think lounging on the couch watching TV or long distance running. Since we have such large fat stores in our bodies (compared to our carbohydrate storage) we are able to do these activities extremely efficiently as the fat stores are vast sources of fuel. As the exercise intensity increases, there is a gradual shift from fat to carbohydrate as the body’s preferred source of fuel. What this means for us, is that our diet should be balanced across all macronutrients as we dabble in all types of exercise (constantly varied, right?). As I mentioned above, figure out the protein and the carbohydrates, and the fat should work itself out!