Healthy Fat vs. Unhealthy Fat: What's the Difference?
Healthy Fat vs. Unhealthy Fat: What's the Difference?
What comes to your mind when you think of fat? Do you believe it’s good, bad, or are you indifferent? There are many varying viewpoints, and studies show about half of consumers are confused and don’t know which are good or bad. Let’s clear up some confusion by exploring the different types of fats.
The truth is your body needs fat, and knowing what kinds to consume that provide energy and support growth, and which to avoid that detract from your health doesn't have to be complicated. Let’s clear up some confusion by exploring the different types of fats, dispel the myth that all fats make you fat, and banish the demonization of an essential nutrient.
Healthy Fat vs. Unhealthy Fat
Fat is the most concentrated source of energy available to the body. It is also one of the three macronutrients you eat—the other two are proteins and carbohydrates. It’s important to realize that all foods containing fat have a mixture of different types of fats. The most common types of fat in your body are called triglycerides, which is made up of a glycerol molecule with three fatty acids attached.
Fatty acids are classified in the following ways: monounsaturated, polyunsaturated, saturated, and trans. Their carbon structures vary in length and are categorized as a short, medium, or long chain. These lengths determine their function in addition to whether or not they have a double bond. To keep things simple, monounsaturated fats contain one double bond, and polyunsaturated fats contain more than one double bond (n-3 and n-6). “It is the differences in chain length and saturation status that dictate their performance in food and cooking, as well as their role in the body and impact on human health and disease,” according to the Academy of Nutrition and Dietetics.
Let’s explore each classification individually to determine their health-promoting or -demoting properties. Get ready to expand your healthy vs. unhealthy fat knowledge.
Monounsaturated Fatty Acids (MUFAs)
MUFAs are made by your body and synthesized in the liver in response to carbohydrate consumption. Your body uses MUFAs in many different ways. They tend to be liquid at room temperature. Olive oil is an example of a MUFA; almonds, pecans, cashews, and avocados are also sources of healthy monounsaturated fats—all with the main component of oleic acid, which is abundant in both animal and plant sources. Oleic acid is the largest MUFA found in Western diets.
Monounsaturated fats have been shown to have the following benefits:
Polyunsaturated Fatty Acids (PUFAs)
PUFAs must be obtained from the foods you eat; therefore, they are considered essential. These fatty acids remain liquid even when refrigerated. Omega-3 fatty acids are a key family of polyunsaturated fats, as are omega-6 fatty acids. On exposure to air, these fats oxidize easily, meaning they become rancid. When fats and oils oxidize, research shows they “may have altered biological activity making them ineffective or harmful.” Polyunsaturated fats oxidize more readily than monounsaturated fats, and monounsaturated fats oxidize faster than saturated ones.
Research shows that a combination of the Industrial Revolution, the rise of agribusiness with processed foods, grain-fattened animals, and the hydrogenation of vegetable oil have all reduced the content of omega-3 essential fatty acids in today’s Western diet. In addition, the typical American diet has excessive amounts of omega-6 compared to that of your ancestors. Research shows that too much omega-6 in the diet can create an imbalance that may interfere with important prostaglandins. Prostaglandins are a family of hormones that mediate inflammation. The body makes prostaglandins out of fatty acids from dietary sources, so when an inflammatory response persists for too long, inflammation itself produces disease rather than healing. In the past few decades the consumption of omega-6 fatty acids has increased, while the consumption of omega-3 fatty acids has decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 to 20:1 today or even higher.
In Dr. Andrew Weil’s book 8 Weeks to Optimal Health, he explains that “some fatty acids, like those in the in safflower oil, corn oil, and margarine, favor the synthesis of prostaglandins that promote inflammation; others like omega-3s in fish oils, favor the synthesis of the inhibitory prostaglandins.” However, when polyunsaturated omega-3 fats and omega-6 fats are consumed equally (1:1 ratio), they have been shown in studies to support the following:
The best sources of omega-3 fats include wild small cold water fish (e.g., salmon, mackerel, anchovies, sardines, and herring), pasture-raised eggs, seeds (e.g., chia and flaxseeds), and nuts (especially walnuts). Algae are also a great option.
According to Dr. Weil, high levels of omega-6 fatty acids are found in processed and fast foods, as well as in polyunsaturated vegetable oils like corn, sunflower, safflower, soy, and cottonseed. The primary food sources of omega-6 fatty acids consumed in the United States are poultry, grain-based desserts, salad dressing, potato/corn/other chips, nuts and seeds, and pizza.
Saturated Fatty Acids
Saturated fatty acids are solid at room temperature and are found in dairy foods such as whole milk, butter, ghee, cream cheese, and meats. Some plant products including coconut oil and palm oil are also high in saturated fats.
The benefits of saturated fats have been fiercely debated since the demonization of saturated fat by Dr. Ancel Keys, who led the anti-saturated fats charge. Dr. Keys published a paper on the relationship between saturated fat and heart disease, which examined the differences in disease rates among people in his study by looking at the composition of their diet—especially levels of saturated fatty acids and mean serum cholesterol levels—and how they predict current and future population rates of coronary heart disease.
In contrast, the Framingham Heart Study, a population-based, observational study was initiated by the United States Public Health Service to investigate the epidemiology and risk factors for cardiovascular disease; this study raised questions about Dr. Keys’s findings. The results of the Framingham Heart Study elaborates on multiple concepts and practical tools in the identification and prevention of elevated cardiovascular risk such as “multivariate risk,” which is “the more-than-additive contribution to risk of multiple factors present together,” among others.
Recent studies show that not all saturated fats are equal, and that some play a more protective role in health and heart disease than once thought. Rather than being dangerous, saturated fats support your health in the following ways:
The biggest food sources of saturated fat in the United States are cheese, pizza, dairy and grain-based desserts, chicken, and meat products like sausage, bacon, beef, and hamburgers.
In his book What the Heck Should I Eat?, functional medicine expert Dr. Mark Hyman offers some simple dietary guidelines: “Eat high-quality, organic, grass-fed, sustainably raised meat as part of an overall healthy diet.” He further explains when you consume saturated fats from meats, the best kind to eat are grass-fed meats like beef, and others like lamb, elk, and venison. The meats to avoid are factory-farmed concentrated animal feeding operation (CAFO) animal foods and those treated with antibiotics or hormones. Dr. Hyman also suggests for poultry, pasture-raised chicken, turkey, and duck are good sources of animal-based saturated fats. And finally, grass-fed butter or ghee, and plant oils like virgin coconut oil and sustainably sourced palm oil are good options in moderation.
Trans Fatty Acids
Trans fatty acids, the fourth type of fat, are a derivative of industrial processed fats and are considered a “bad” fat as they increase your risk for cardiovascular disease. They are mostly man-made fats that have become a significant part of the American diet. Walter Willet, M.D., author of Eat, Drink and Be Healthy, shares that his research shows trans fats fire inflammation, which plays a key role in the development of heart disease, diabetes, and probably other leading causes of death and disability. When determining whether a food item contains trans fat, check for hydrogenated or partially hydrogenated oils on food labels; these are also known as trans fats. Additionally, Dr. Willet observes, “The rise in amount of trans fats made and eaten in the United States suspiciously parallels with the rise in heart disease throughout much of this century.” The US Food and Drug Administration ruled in 2015 that partially hydrogenated oils are no longer “generally recognized as safe” and should be removed from the food supply.
That being said, it is important to read labels carefully as trans fats are widely included in cookies, fried foods, crackers, snack foods, spreads, and a host of other foods in the grocery store. Though food manufacturers are required to label trans fats in food products, be aware that labels can list 0 grams if the trans fat content is under 0.5 grams.
Another way to assess whether foods have trans fats in them is if it can sit in your cupboard without getting spoiled for months at a time. If they can, it’s the trans fats that are likely keeping them “fresh.” Trans fats are the worst type of fat for the heart, blood vessels, and rest of the body and should be avoided because they:
Promote obesity and resistance to insulin in animal studies.
Fats Serve Many Functions
Fat serves many purposes, and most are positive. Aside from the characteristics mentioned above, fat is a carrier of flavors and tastes throughout the mouth and across the taste buds, and it makes food taste good! It reduces the release time of sugars into the bloodstream, and it provides a sense of satiation, or feeling of fullness. Fat increases the bioavailability of essential fat-soluble vitamins such as A, D, E, and K and is crucial for brain health and many other vital organs. It also can improve your mood!
“Fat helps give your body energy, protects your organs, supports cell growth, keeps cholesterol and blood pressure under control, and helps your body absorb vital nutrients. When you focus too much on cutting out fat, you can actually deprive your body of what it needs most,” says Vasanti Malik, research scientist with the Department of Nutrition at Harvard’s T.H. Chan School of Public Health. Additionally, your brain is nearly 60 percent fat, which determines your brain’s integrity and ability to perform. A study on mice found that fat strengthened bones because it allows for calcium to be absorbed more efficiently, especially monounsaturated fats. Last, but definitely not least, research is also underway with looking at how fat may help with depression.
Fat as Your Friend
Hopefully by now you have a better idea of what are healthy fats that help your body thrive, and are aware of the ones that deprive your body of good nourishment. The Heart and Stroke Foundation of Canada’s director of policy and advocacy, Manuel Arango, shares a simple message to put all this information to good use: “If you eat a balanced diet, don’t fret about the fat. Cut the crap. Cut the highly processed foods.” Find ways to get creative in your kitchen by cooking and eating more at home, by consuming organic, high-quality whole, fresh, foods as much as possible, and enjoying the delicious flavors and benefits fat has to offer.