A long time ago (i.e., in the 90's), fats were held responsible for the increase in incidence of heart disease and obesity in America. Because of this, Americans were encouraged to focus on reducing their fat intake, leading to a surge in the availability of low-fat and fat-free food products. However, what replaced the fat in processed foods became the next generation's problem: sugar (but I'll save this topic for another post...).
Nowadays (just a mere twenty-five years later) we know much more about the role of fat as related to heart health and weight management. We now understand that fats, specifically those of the unsaturated variety, are both vital, as well as beneficial to our health. We need dietary fat to absorb the fat-soluble vitamins A, D, E, and K, and to meet our energy needs.
So, what are these healthy, unsaturated fats? Simply put, unsaturated fats are derived from plant sources, and are most often liquid at room temperature. Unsaturated fatty acids are divided into two subgroups: polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs). While both PUFAs and MUFAs are healthy fats, each contain unique characteristics, offering unique health benefits:
PUFAs: Chemically, polyunsaturated fatty acids have more than one unsaturated carbon bond (i.e., a double bond). Nutritionally, PUFAs have been shown to help lower LDL ("bad") cholesterol levels, thus lowering your risk of both heart disease and stroke (1). PUFAs also provide vitamin E, an antioxidant vitamin that can help control inflammation and free-radical oxidation throughout the body (2). Finally, PUFAs include fats known as essential fatty acids (fats our bodies cannot make on their own), including both omega-6 and omega-3 fatty acids (more on these below). Again, because we are not able to produce these on our own, we MUST consume these via food.
MUFAs: Chemically, monounsaturated fatty acids contain just one unsaturated carbon bond. Similarly to PUFAS, MUFAs can also help reduce LDL ("bad") cholesterol levels, lowering your risk of both heart disease and stroke (1). Research also shows that MUFAs may benefit insulin / blood sugar levels, which can be particularly helpful for those with diabetes (3).
What about saturated fats? Saturated fats are generally found in animal products (meat, poultry, fish, eggs, and dairy), and are solid at room temperature. However, there are some plant sources that provide saturated fats; these include, coconut, coconut oil, palm oil, palm kernel oil, and cocoa butter. Nutritionally, saturated fats (when eaten in excess) have been shown to raise blood cholesterol levels (4). So, eat saturated fats in moderation, and choose mostly unsaturated fat sources for maximum health benefits.
How much? In general, it is recommended that fat make up between 20-35% of our total daily Calorie intake – only 7-10% of which should be saturated.*
Without further adieu, read below for my top 5 Sources of Healthy Fats (in no particular order):
1. Nuts + nut butters. All nuts / nut butters are an excellent source of both poly- and monounsaturated fatty acids. My appointed star of the nut category is the beautiful, brain-shaped walnut. Walnuts are uniquely high in omega-3 fatty acids (a PUFA). Omega-3 fatty acids are anti-inflammatory, and offer a variety of health benefits, including lowering your risk of coronary heart disease and improving blood cholesterol levels. There have also been promising results from studies looking at omega-3 fatty acids for cancer, depression, and attention-deficit hyperactivity disorder (ADHD) (5). Pecans, hazelnuts, macadamia nuts, and almonds are particularly high in monounsaturated fatty acids; however, all nuts provide a good amount of MUFAs (6).
✓ Serving recommendation: 1 handful, or about ¼ cup.
2. Seeds. Similar to nuts, seeds are packed with both poly- and monounsaturated fatty acids. My seed stars include ground flaxseed (we are unable to digest whole flaxseeds), chia seeds, and hemp seeds, as these all contain a good portion of those anti-inflammatory omega-3 fatty acids (as mentioned above). Sesame and sunflower seeds are high PUFAS, particularly omega-6 fatty acids. Omega-6 fatty acids, while necessary in the diet, are pro-inflammatory and tend to be over-consumed in the American diet. However, when omega-6 fatty acids replace saturated fats in the diet, they contribute positive effects on blood cholesterol levels and heart health (1).
✓ Serving recommendation: 1 handful, or about ¼ cup.
3. Avocado. If you've ever met me, you may know that I LOVE avocados – and for good reason! Avocados are not only loaded with monounsaturated fatty acids, but also provide a significant source of fiber, potassium, vitamin C, vitamin E, folate, and many other vitamins and minerals. And don't just think guacamole when you think avocado; add avocado to smoothies, salads, tacos, burgers, eggs, sandwiches, or on toast (pictured); the mild flavor and creamy texture compliment a wide variety of dishes. Give this amazing fruit (yes, it's technically a fruit nutritionally classified as a vegetable) a try for yourself!
✓ Serving recommendation: ¼ - ½ avocado (varies depending on avocado size and usage).
4. Oils. Almost all oils are unsaturated (except for palm and coconut oils), as they are liquid at room temperature. My top oil recommendation for all of your general cooking / dressing needs is a high-quality extra virgin olive oil. Olive oil is primarily made up of monounsaturated fatty acids. "Extra virgin" indicates that the oil is made simply by crushing olives and extracting the juice – it is free from the the use of chemicals and industrial refining. However, extra virgin olive oil does have a lower smoke point (the temperature at which the oil breaks down to where possibly harmful compounds are formed), so use this oil only when cooking on low- / medium-heat, or in cold dishes.
✓ Serving recommendation: 1 tablespoon for low- / medium-heat sautéing and dressing cold dishes / salads.
5. Fish. Last, but certainly not least, fish (of the fatty variety) provide a significant source of those touted omega-3 fatty acids. My top fish recommendations include salmon, albacore tuna, mackerel, lake trout, Alaskan halibut, sardines, and herring – all of the wild-caught variety, if possible. Different types of white fish are healthy in that they are low in Calories and high in protein; however, most of these fish lack these heart-healthy omega-3 fatty acids and are lower in other beneficial nutrients.
✓ Serving recommendation: 4-6 ounces.
Bottom line: Don't be afraid of fats – we need them! Work to incorporate more heart-healthy, unsaturated fats and less saturated fats. Continue to watch your portion sizes – all fats, unsaturated or saturated, are high in Calories, so use them mindfully and in moderation!
*This may vary depending on individual disease states and/or conditions. Do not change the composition of your diet without first discussing with your physician and/or registered dietitian.