Nowadays it seems like every fad diet involves fats in one way or another. There are diets that recommend eating a lot of fat, like a ketogenic diet (high fat, moderate protein, low carb diet that forces your body to use ketone bodies for a source of fuel) or a high fat low carb diet (HFLC). Then there are those diets that limit fat intake, such as a low fat diet or a high carb low fat diet (HCLF, common among vegans).
All fats are not created equal. Some fats—such as monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs)—have amazing cardiovascular benefits, whereas others—such as trans fatty acids (trans fats)—actually increase cardiovascular disease risk factors.
Monounsaturated Fatty Acids (MUFAs)
MUFAs decrease serum cholesterol levels, low-density lipoprotein (LDL, “bad”) cholesterol levels, and triglyceride levels, and raise high-density lipoprotein (HDL, “good”) cholesterol levels. They lower mortality rates of cardiovascular disease and decrease risks of certain types of cancer and neurodegenerative diseases.
Sources: Olive oil, olives, canola oil, peanut oil, peanuts, peanut butter, poultry, avocados, almonds, cashews, pistachios, pecans, macadamia nuts
Polyunsaturated Fatty Acids (PUFAs)
Omega-6 fatty acids: Omega-6 fatty acids lower total cholesterol and LDL cholesterol levels
Sources: Safflower oil, corn oil, soybean oil, sunflower oil, walnuts, pine nuts, mayonnaise
Omega-3 fatty acids: Omega-3 fatty acids lower triglycerides and lowers your risk of heart disease by 1) decreasing clot formation, 2) decreasing vasoconstriction, and 3) decreasing inflammation
Sources: Salmon, herring, anchovies, sardines, mackerel, fatty fish, shellfish, nuts, flaxseed, canola oil, and soybean oil
Saturated Fatty Acids (SFAs)
These are mostly found in meat and dairy products (e.g., animal fats, lard, milk fat, butter, cheese, yogurt, ice cream, cream, sour cream). They are also found in palm kernel, coconut, and palm oils. These should be restricted because they have the most potent effect on LDL cholesterol, which rises when increasing levels of SFAs are consumed. Of all the added fats in the diet, the ones that increase cholesterol levels the most are palm kernel, lard, and butter.
No more than 7 percent of our calories should come from SFAs.
Trans-fatty Acids
These are produced in the hydrogenation process, which is used in the food industry to increase the shelf life of foods and to make margarines firmer. Trans-fatty acids should be limited because they raise LDL cholesterol and increase the LDL:HDL cholesterol ratio, thus adversely influencing your risk of cardiovascular disease.
Sources: Most trans-fatty acid intake comes from partially hydrogenated vegetable oils, stick margarine, non-dairy creamers, solid shortening, cookies, pastries, doughnuts, and crackers
No more than 1 percent of calories should come from trans-fatty acids.
Dietary Cholesterol
Dietary cholesterol raises total cholesterol and LDL cholesterol but to a lesser extent than SFAs.
Sources: Egg yolks, liver, organ meats, squid, abalone (one egg yolk has ~200 mg cholesterol; meats, fish, poultry, and shellfish 20–30 mg/oz; shrimp 40–50 mg/oz)
Now that you are overwhelmed with all of the different types of fats, their food sources, and health benefits or lack thereof, what’s next?
Take a good look at your diet and analyze what types of fats you are consuming. If you are consuming a lot of processed foods, there’s a good chance you are consuming trans fats, because they are often used to make products shelf stable and have a longer shelf life. If you’ve been told by your doctor to increase your omega-3 intake, you may benefit from increasing the amount of fatty fish, nuts, and flaxseed in your diet.
Not all fats are created equal, and they certainly don’t all have the same health benefits. Consult with your doctor or healthcare provider before embarking on any diet.