Over the years people have been conditioned to view fat as a dietary enemy because of the high calorie composition and the association of trans- fats, saturated fats and cholesterol to heart disease. But the good new is that not all fats are created equal and fats play a vital role in overall health.
Some of the roles fats play within the human body are:
- Fat is required for the absorption and storage of the the fat soluble vitamins A, D, E, & K.
- Fat helps insulate the body to maintain normal body temperature.
- Fat surrounds vital organs, protecting them from external impact.
- Protective membranes that line the outside of every cell in the body is made primarily of fat.
- Fat helps regulates hormone levels.
Types of Fats
As stated earlier, fats are not created equal. Fats are divided into four broad categories; saturated, trans, monounsaturated, and polyunsaturated. Saturated fat and trans-fats are considered least healthy when compared to monounsaturated and polyunsaturated.
Saturated fatty is a fat that is solid at room temperature and is mainly found in animal products. Major sources of saturated fat include cream, butter, milk, beef, and processed meats, skin of chicken, lard, and pastries. Eating excess amounts of saturated fats is unhealthy because they are known to raise LDL (bad) cholesterol and triglyceride levels which can increased the risk of developing arthrosclerosis (hardening of arteries).
Trans-fats acids are similar to saturated fats since they are usually found in the same foods and they are solid at room temperature. But most trans-fats are industrially made by adding hydrogen to liquid vegetable oil to make them more solid. Like saturated fats, trans-fats are known to raise LDL-cholesterol levels, but unlike saturated fat they also lower HDL-cholesterol levels causing an increased risk of Coronary Heart Disease. The American Heart Association recommends consuming less than 1% of your total daily calories from trans-fat. Food manufactures use these TFA during production, because they are easy to use, inexpensive to produce, and they increase the shelf life of processed foods. Major sources of trans-fat for American adults come from cakes, cookies, pies, potato chips, and buttered popcorn.
Monounsaturated fats are among the healthiest of all fats. The prefix “mono” is used in terms of the structure of these fat molecules since they have only one double bond in the fatty acid chain. When consumed in moderation they can have beneficial effects lowering bad cholesterol and improving blood sugar control when used in place of trans and saturated fats. Sources of monounsaturated fats include avocados, almonds, cashews, peanuts, olive oil, and olives.
Instead of having one double bond in the fatty acid chain like monounsaturated fats, polyunsaturated fats have many double bonds. These fats can be further broken down in omega-6 and omega-3 fatty acids. The polyunsaturated fats linoleic and alpha-linolenic are considered essential since the body can’t produce them on their own.
Omega – 6
These are derived from the essential fatty acid linoleic acid. Omega-6’s are found in seeds, nuts, grains, and vegetable oils (corn, soybean, cottonseed, sesame, sunflower). Most diets provide more than enough of these fatty acids, so planning is rarely required to ensure proper amounts of omega-6 fatty acids are consumed.
These are derived from the essential fatty acid alpha-linolenic acid (ALA), which is further converted to eicosapentaenoic acid (EPA) and docosahexaenonic acid (DHA) by the body. Omega-3’s have many health benefits such as lowering blood pressure and triglyceride levels, improving eye health, brain development, reducing the risk of certain cancers and diabetes, and acting as an anti-inflammatory. Plant-based sources of Omega 3’s are walnuts, flaxseeds, soybeans; algae based Omega-3 supplements, and chia seeds.
I want to use this last section to discuss my opinion on using oils. Most people fail to realize that oils are the most concentrated source of calories you can eat. When compared to the whole foods (ex. Olives vs olive oil) oils are vastly deficient in nutrients. When compared to animal derived fat, oils are a better choice; however nuts, seeds, olives, and avocado are a better choice than oils. So instead of drenching your salad with olive oil, try topping it with hemp, flax, almonds, or chia.