A Complete Guide to Fats
From the ones you should be eating more of to the ones to avoid.
Omegas, saturated, polyunsaturated, trans-fatty acids—there are a lot of different types of fats out there, and it's easy to confuse the good and the bad. But establishing a healthy diet requires understanding their differences. This begins, says Melissa Majumdar, the spokesperson for the Academy of Nutrition and Dietetics, by learning how fats are categorized—which ultimately comes down to their chemical structures. While some fats are actually man-made and should be avoided, others are natural and integral to building and maintaining good heart health. Ahead, everything you need to know about each type of fat.
Saturated fats are saturated with hydrogen atoms, meaning they have no double bonds and are most often found in cheese, spreads, salad dressings, poultry with skin, fatty beef, and butter. As for how much of these fats you should eat? The Dietary Guidelines for Americans 2015-2020 suggest we consume less than 10 percent of our daily calories from saturated fats. The American Heart Association suggest five to six percent of calories from saturated fats.
Also known as trans fats, trans-fatty acids are man-made; oils are partially hydrogenated— which means that hydrogen atoms are added—to make the fats more shelf stable. In doing so, the hydrogenation process creates a fat that our body does not natively produce or understand how to process—which is ultimately why these fats can lead to heart disease. As you'd expect, trans fats are culprits in processed foods, including everything from baked goods and margarine to packaged snacks and fried foods. Just as understandable? Both the Dietary Guidelines and the American Heart Association agree that trans fats should be avoided altogether.
Unsaturated fats are fatty acid chains with one double bond (monounsaturated), or more than one double bond (polyunsaturated). Olive and canola oil, avocado, nuts, seeds, and tofu have plenty of good-for-you unsaturated fats; you'll notice that all aforementioned foods are widely considered to be healthy. There's a reason for this: The vast majority of the fats you consume should be either monounsaturated or polyunsaturated, says just about every healthcare provider out there. Adds Majumdar, "We can swap saturated fats with unsaturated fats by relying on seafood and fatty fish for our protein source, choosing oils like olive and canola oil for cooking, or opting for oil-based instead of creamy dressings," she explains. These tweaks are more than worth it: "We know that replacing just five percent of calories from saturated fats with unsaturated fats helps reduce the risk of heart disease by 42 percent."
Omega-3 Fatty Acids
These fatty acid chains have three double bonds and are found in fatty fish like salmon, albacore tuna, and anchovies, as well as walnuts, seaweed, flaxseeds, and chia seeds. "The average American is not eating enough omega-3 fatty acids—this is the fat that makes fish the superstar," says Majumdar. "Most of us are eating three ounces of fish weekly, falling short of the recommended eight to 12 ounces per week."
Why does the kind of fat you consume matter?
Ultimately, understanding how fats impact your body is critical, since choosing too many of the "bad" types can lead to poor heart health. "Most Americans exceed the recommendation for saturated fats. Saturated and trans fats, are associated with higher LDL (bad cholesterol levels), while unsaturated fats, are associated with higher HDL cholesterol," explains Majumdar. "LDL cholesterol clogs arteries, while HDL is the street cleaner, helping to move the LDL swiftly through the arteries, thus avoiding the waxy buildup. Higher LDL levels and intake of saturated and trans fats has been associated with heart disease." By sticking with the recommended fat intake, you can lower your risk of heart disease—and maintain a healthier diet overall.