It seems like lately we’re constantly being bombarded with advertising campaigns that proclaim “Zero Grams Trans Fat!” or “Now with Omega-3s!” But why do these things truly matter, you ask, if the products still contain fat? When you think of the word “fat,” all you can see are your cottage cheese thighs or your multiple chins, right? But fat isn’t just a result; it’s also a vital dietary element. Your body needs fat—it just needs the right kinds. The Weekly has your fat crib sheet on the good, the bad and the ugly.
You actually have to eat fat in order for your body to function properly. According to the Mayo Clinic, fat is a nutrient used in the production of cell membranes, as well as in several necessary hormone-like compounds called eicosanoids, which help regulate blood pressure, heart rate, blood vessel constriction, blood clotting and the nervous system. Dietary fat also carries fat-soluble vitamins—A, D, E and K—from food to your body, and helps maintain healthy hair and skin, protects vital organs and keeps your body insulated.
But that doesn’t give you a license to gorge on Cheetos and Twinkies. According to the Harvard School of Public Health, the biggest influence on your blood cholesterol level is the mix of fats in your diet. Cholesterol is a wax-like substance produced by the liver which, when linked to carrier proteins called lipoproteins, dissolves in the blood and travels throughout the body to aid in the formation of cell membranes, some hormones and vitamin D. Yes, cholesterol is actually a good thing, but, as usual, too much of a good thing is a very bad thing. Excess deposits of cholesterol can build up inside the arteries and block blood flow, leading to chest pain, heart attack, stroke or sudden death. Cholesterol-carrying lipoproteins come in two varieties. Low-density lipoproteins (LDL) carry cholesterol away from the liver to the body and, when in excess, cause buildup, thus LDL is often referred to as “bad” cholesterol. High-density lipoproteins (HDL) carry that excess cholesterol from the blood back to the liver, where it’s processed and eliminated. In other words, while some fats increase your risk for certain diseases (obesity, diabetes, heart disease, cancer, and osteoarthritis), other fats can actually lower that risk.
An easy way to determine a good fat is if it stays liquid at room temperature. Look for monounsaturated (avocados, nuts and olive, canola and peanut oil) and polyunsaturated (corn, soybean, safflower and cottonseed oils) fats—they lower your LDL while raising your HDL. Omega-3 fatty acids are a special kind of polyunsaturated fat. The best sources are fatty, cold-water fish, such as salmon, mackerel and herring, but you can also find them in walnuts, flaxseed products and soybean and canola oils. There’s a whole laundry list of benefits associated with Omega-3s, including anti-inflammatory properties, aiding in infant development and helping to ease depression.
Bad fats, on the other hand, are generally solid at room temperature. Try to limit your consumption of saturated fat (whole milk, butter, cheese, ice cream, red meat, chocolate and coconut products). It raises your HDL, but also your LDL.
Trans fat is your truly ugly fat. Solid or semi-solid at room temperature and mostly man-made, trans fat (margarines, vegetable shortening, partially hydrogenated vegetable oil, many fast foods and most commercial baked goods) raises LDL while actually lowering HDL. It’s so bad for you that cities and states are beginning to ban it entirely.
Fat, even the good stuff, is high in calories—pick foods that have healthful properties and enjoy them in moderation.