Everything You Need to Know About Dietary Fats
In the past, dietary fat was public enemy no. 1 due to its perceived connection to obesity, diabetes, cancer, and other chronic ills. The recent rise in low-carb, paleo, and keto diets brought fat back into the spotlight. It has forced people to re-examine their relationship to this misunderstood nutrient.
Not all fats are created equal. Read on to learn more about fat’s role in the body, how to tell the difference between good and bad fats, and some healthy fat sources.
What Are Dietary Fats?
Dietary fats are the fats and oils naturally found in animal and plant foods. But foods contain varying amounts of fat and varying types of fat. Fruits, vegetables, reduced-fat dairy, lean protein, and minimally processed grains are on the low-fat spectrum. Many cuts of meat, full-fat dairy, eggs, and some fish have more fat. Cooking oils and butter are almost 100 percent fat.
Why Is Fat Good For You?
According to Samantha Thoms, MPH, RDN, and owner of Budget Dietitian, “Dietary fats are one of three essential sources of fuel. Fat is an energy source that contains nine calories per gram, while the other two groups of energy sources, carbohydrates and protein, each contain four calories per gram. But fat’s role goes beyond calories. You need it to:
- Form and cushion everything. Fat is in every cell membrane and makes up 60% of the human brain.
- Assist in absorbing specific vitamins and minerals. Fat-soluble vitamins like A, D, E, and K are better absorbed with a diet adequate in fat.
- Help with satiety and regulate appetite. Foods that contain fat may support satiety by slowing down digestion.
- Provide omega-3 and omega-6 fatty acids. These are called essential fatty acids because your body cannot make them on its own; they must come from the foods you eat.
Dieters used to ditch high-fat foods thinking it would help with weight loss, but that’s no longer true. When asked if you should avoid fat, Denis Faye, Executive Director of Nutrition for Openfit, emphatically says, “No way! Fat is a vital nutrient.” Read the full explanation in: Ask the Expert: Should You Avoid Fat?
Different Types of Fat
Fats are classified based on their different chemical structures and are often characterized as “bad” fats and “good” fats. Here’s the breakdown on the different types, and the benefits or risks of including them in your diet.
1. Saturated fats
Dietary saturated fats most often come from animal-based food sources, with a few exceptions: palm and coconut oil. Foods with substantial saturated fat are certain cuts of beef, lamb, pork, and chicken (skin on), as well as lard, butter, and full-fat dairy products.
The stance of the American Heart Association, American Diabetes Association, and American Cancer Society: Saturated fat is unhealthy, so avoid it if you can. It’s saturated fat’s structure that causes it to be solid at room temperature, e.g., butter, lard, and coconut oil. This is also why many experts believe overdoing saturated fat can have the potential to negatively affect your cardiovascular system when consumed in excess over time.
The dust hasn’t settled on this debate. Some experts argue that diet is more nuanced than chemical bonds, nutrition research isn’t a perfect science, and the connection between saturated fat and heart disease continues to be studied. Genetics, other risk factors, and lifestyle are also important to consider, which adds to the debate and difficulty when determining how much our intake of saturated fats affects our health.
2. Unsaturated fats
Unsaturated fats mostly come from plants. They’re deemed the “good” fats and are liquid at room temperature. Research suggests that eating foods high in monounsaturated or polyunsaturated fats are better for your overall heart health compared to saturated fats. There are standouts within the unsaturated fat family:
- Omega-3 fats. Found in foods like fatty fish and flaxseeds.
- Omega-6 fats. Found in vegetable oils such as corn, safflower, and soybean.
These fatty acids are believed to be beneficial to your overall health. In addition, your body is unable to create some of the fatty acids found within omega-3s and omega-6s, which increases the importance of getting them from dietary sources.
3. Trans fats
Also known as “partially hydrogenated oil,” trans fats are man-made by a process called hydrogenation, which changes a liquid oil to one that is solid. The result is a shelf-stable fat that research has found to have negative effects on your health.
Fat & Cholesterol: What’s the Difference?
Says Thoms, “Fat is a macronutrient, meaning it’s an energy source for the body. Cholesterol is a type of fat, but it’s not an energy source.” Our bodies actually make cholesterol, which is needed for a number of functions. For instance, cholesterol is a major component in the human brain, which holds 20 percent of the body’s cholesterol supply. It’s also a building block for every cell membrane.
What about cholesterol in the diet?
This has been a long-debated topic. Let’s catch up on the controversy: For decades, the American Heart Association recommended limiting your cholesterol intake to less than 300 milligrams per day, but in the 2015–2020 Dietary Guidelines for Americans, the federal government lifted this restriction. The guidelines stress, however, that this does not mean a free-for-all when it comes to eating high-cholesterol foods. It is still important to consider healthy eating patterns and recognize that many cholesterol-containing foods are also high in saturated fat like full-fat dairy and certain cuts of meat. Certain foods like eggs and some shellfish are higher in cholesterol but not saturated fats. These types of foods are believed to be less “unhealthy” than foods containing significant levels of saturated fat and cholesterol. The dietary guidelines state: “Eggs and shellfish can be consumed along with a variety of other choices within and across the subgroup recommendations of the protein foods group.” Read more opinions in: Are Egg Yolks Bad for You After All?
What Should My Daily Fat Intake Look Like?
Adults should get 20 to 35 percent of total calories from fat, and on average, Americans are meeting their needs by hitting the upper end of that range. Says Thoms, “Vegetarians and vegans should pay special attention to omega-3 intake. Supplement as needed, but you should talk to your doctor first.” She emphasizes getting your fat from healthier food sources (see more below).
Current recommendations are to limit saturated fat intake to less than 10 percent of your calories per day. But Faye argues that it’s shortsighted to lump all saturated fats together. He leans on the growing research that not all saturated fats are the same, pointing out that lauric acid (found in coconuts) is a medium-chain saturated fat with a few potential benefits, including functioning better than most fats as a fuel source and supporting overall heart health.
Healthy Food Sources High in Fat
It’s easy to get stuck on conflicting media headlines about fat and the keto diet, and not make a change to better your current diet. But adding these delicious, high-fat foods to your balanced diet is definitely a win — no contest.
1. Extra-virgin olive oil
More than half of the fat in avocados comes from monounsaturated fat. This nutritious fruit also contains fiber, potassium, folate, and vitamins B6, C, and E. All the more reason to love your avocado toast!
With nuts, you’ll score a good mix of unsaturated fats, protein, fiber, minerals, and antioxidants. Most nuts carry a little saturated fat, but a lot of mono- and polyunsaturated fats. Snack on almonds, cashews, peanuts, and pistachios, and don’t forget a jar of your favorite nut butter. Vegetarians will benefit from walnuts, which are a good source of ALA (a plant-based omega-3 fat).
Seeds also contain mono- and polyunsaturated fats as well as calcium, zinc, copper, and magnesium. These minerals are especially important for vegetarians and vegans. Sprinkle some chia, flax, hemp, pumpkin, or sunflower seeds over oats.
5. Salmon and other fatty fish
Kick your egg anxiety to the curb! Eggs are a nutrient-dense, budget-friendly protein source. A large egg yolk does contain 1.6g of saturated fat, but well worth it because eggs are packed with almost all of the B vitamins, vitamins A and D, choline, phosphorus, iodine, and zinc.