Let’s be honest, we’ve all eaten foods high in fat. Did you happen to feel guilty after that insanely satisfying meal? Perhaps the satiety haunted you for hours because you unknowingly ate too much? Did you convince yourself that the fat you just consumed was going to go straight to your love handles? This is a post about what fats, also known as lipids, are and how they work in the body. I’m going to explain to you why eating a certain amount of fat is actually necessary in the diet and that there are such things as good fats that won’t actually cause you to pack on pounds. Yay!
Before I begin I want to point out that lipids are energy dense as they contain 9kcal/gram. Essentially, lipids come in three different types: triglycerides, phospholipids, and sterols. In an effort to not bore you to death with detail, or confuse you with scientific vernacular, I’m going to cut to the chase when it comes to describing each of these.
Triglycerides make up 95% of the fats present in our diet and are composed of a molecule of glycerol attached to three fatty acid chains. The fatty acid chains are what concern us the most because they are what constitute for saturated fatty acids and unsaturated fatty acids (I’m sure you’ve heard these terms before). Saturated fatty acids are predominately present in animal based products including processed meats such as sausages, hot dogs, and bacon, dairy products such as cheese, butter or margarine, milk, and eggs, as well as certain plant foods such as coconuts, and other various nuts. A good way to tell if an oil contains saturated fat or not is by seeing if it’s solid at room temperature. Unsaturated fatty acids are more readily broken down in the body and can be split into two categories: polyunsaturated fats and monounsaturated fats. These are the fats that will not make you fat (when consumed in proper amounts). Polyunsaturated fats are fats that contain many or multiple (poly) double bonds within the fatty acid chain. This allows for fluidity, and easy breakdown. Monounsaturated fats are fats that contain one (mono) double bond within their fatty acid chain. Your diet should be limiting in saturated fatty acids, and plentiful in unsaturated fatty acids. However, consumption of some saturated fat is necessary depending on the source of such fats according to researchers at Harvard University, (which is something I’ll get into another time) so don’t skip out on saturated fats completely. I’m not at all saying it is okay to consistently consume processed meats or other processed foods, I’m just saying, don’t kill yourself over trying to completely rid saturated fat from your diet because that would be unnecessary.
Essential Fatty Acids are lipids which you unequivocally need to consume because your body does not synthesize these! Luckily there are only two of them that you have to keep in mind. By the way, this was my favorite topic in my nutrition class because I had no idea what essential fatty acids did in the body, and when I finally understood their purpose I was more than fascinated, so I hope I can spark a scintilla of interest in you too. The two essential fatty acids are known as Omega-6 and Omega-3. They form what are known as eicosanoids in the body, which are hormone like compounds, but instead of acting in various parts of the body, they only act specifically in the region which they are produced. The biggest thing to understand is that Omega-6 and Omega-3 form contrasting eicosanoids that work to balance each other out, however in order to function, they compete for the same enzyme. Therefore, if you consume more of one fatty acid than another, you can cause an imbalance of blood pressure, blood clotting, inflammatory response, and immune response. Omega-6 eicosanoids are derived from meats and vegetable oils and cause an increase in blood pressure, an increase in the bodies ability to clot blood, increases inflammatory response and immune response. In America, we tend to get more Omega-6 fatty acids, and thus witness the predominant chronic disease killer himself ; cardio vascular disease. Omega-3 fatty acids do just the opposite of Omega-6 fatty acids. I don’t want you to misunderstand me, Omega-6 fatty acids are not necessarily bad, they just need to be balanced with Omega-3 fatty acids in order to maximize their potential. Omega-3 fatty acids come from foods such as flax seeds, hemp seeds, canola oil, soy beans, nuts, and fish.
Phospholipids are another type of lipid which are soluble in water. I’m not going to get too into it, however, I think it’s important to understand that phospholipids are absolutely necessary for fat digestion and absorption because they allows bile to mix with fat. Essentially, without phospholipids, you would not be able to absorb all of the nutrients from fats, nor would you be able to absorb the vitamins A,D,E and K. Phospholipids also assist in eicosanoid production, and they can be found it lecithin containing foods such as eggs, soy beans, and wheat germ. Also, your body makes phospholipids with the fats it consumes, so don’t worry if you don’t eat eggs or soy every single day.
Sterols are the last category of lipid I’m going to entice you with today. Sterols are waxier than the other two types of fat mentioned about. This allows them to play a major role in lipid transport. This is important because throughout the day, the cells in your body need to make things, and thus need to receive the materials necessary for synthesizing whatever it is they wish to create. In order to obtain these necessary materials, they need to be brought to the cell, hence the significance and job of the lipid transporter. One of the most famous sterols I’m sure you’ve heard of is cholesterol. Cholesterol is only found in animal foods, but plants make other types of sterols that you don’t hear about because only cholesterol threatens your health. The USDA recommends less than 200mg cholesterol a day, or you could just go vegan and consume 0mg of cholesterol a day because your body makes all of the cholesterol it will ever need.
You may be thinking: Okay, so fat has different forms, and I need to consume a certain amount of this fat, and not of that fat and oh my, I’m so confused, I’m going to stop reading this, and I’m going to go on Facebook. Have no fear, I will tell you approximately how much of each fat you should be consuming, and some of the food sources from which these fats are derived. All of this information can also be found on the USDA’s website.
- Total Fat consumption: 25%-30% of calories per day. There is no recommended total gram amount.
- Saturated Fat consumption: less than 9% of total calories per day. There is no recommended total gram amount. Saturated fat comes from foods such as french fries, chicken nuggets, burgers, processed meats such as hot dogs and sausages, milk, cheese, eggs, coconuts, various nuts.
- Unsaturated Fats: Should constitute for the remaining 16%-21% of fats consumed in a day after subtracting the 9% of saturated fat. Can be found in foods such as walnuts, soybeans, flax seeds.
- Essential Fatty Acids: Omega-6: 5% or less of calories. Omega-3: 1.2% or more of total calories.
- Trans Fat consumption: I didn’t mention this fat above, however it is a popular fat, especially in the American diet. Trans Fats come from deep fried foods. These fats are not natural, and are instead produced when vegetable oils are heated to high temperatures via hydrolization. This yields an unruly rigidity within the fat making it the hardest to break down and the most dangerous to your heart health. There is no recommended intake of this fat. In fact, you should completely eliminate this from your diet. Trans fat can be found in deep fried foods such ad fried dough, fried chicken and french fries. It can also be found in frosting for texture.
- Cholesterol: For a normal healthy person, 300mg/day of cholesterol can be consumed. For someone who has heart disease or is overweight the American Heart Association recommends that the the intake be lower than 200mg/day. Cholesterol is not necessary in the diet, therefore if you are struggling with heart disease, use your head and cut it out completely. Cholesterol containing foods include all animal based foods including dairy products.