A Dietitian’s Guide on Dietary Fats
When you hear the word fat, what comes to mind? You may associate the word fat with unhealthy, greasy food or something indulgent like chocolate cake.
Unfortunately, fat has gotten such a bad rap due to diet culture and all of its many fad diets. Low fat? High fat? No fat? Dietary fat has been somewhat of a confusing topic for decades now, but the truth is, you shouldn’t fear fat. Fat is an essential nutrient for overall health like absorbing other nutrients, providing satiety, better skin, and brain functioning.
In this blog post, I, a registered dietitian, will be breaking down all things dietary fats: the types of fat, the benefits, the cautions, how much you’re really supposed to eat, simple tips to adding more healthy fats in your diet, and how you can find your balance so that you can feel confident in your food choices.
What Is Dietary Fat?
Fats actually refer to a class of nutrients known as lipids and the lipid family includes triglycerides (fats and oils that are found in food), phospholipids, and sterols.
On a more scientific standpoint, triglycerides contain one molecule of glycerol and three fatty acids. Our bodies break down dietary fats into fatty acids to be sent to the bloodstream and used where needed.
There are different types of fatty acids (dietary fat) and each can serve a purpose for the body, but it’s helpful to keep in mind how much of certain types you’re eating to optimize your overall health.
Types of Fat
There are two main types of dietary fat: saturated fat and unsaturated fat. These terms describe the chemical makeup of each fatty acid.
Saturated fats are typically solid at room temperature and can primarily be found in animal products like beef, pork, and high-fat dairy products like butter, margarine, and cheese. While saturated fats are mostly found in animal-based products, it can also be found in some plant-based products like coconut and palm oil. High amounts of saturated fat are also found in many fast, processed, and baked foods like pizza, desserts, hamburgers, cookies, and pastries.
Unsaturated fats are typically liquid at room temperature and can primarily be found in plant-based products like avocados, almonds, and olive oil. Unsaturated fats are broken down into two types: monounsaturated and polyunsaturated fats.
Let’s dive deeper into the types of fat:
Saturated Fats
Again, saturated fats are mostly found in animal-based foods like meat and dairy. You may have heard people associate saturated fats with “bad” fat. The reason for that is because saturated fats have been linked to increased health risks like cardiovascular disease.
Lowering saturated dietary fats has been a major theme for Dietary Guidelines for Americans, the American Heart Association, and the World Health Organization for decades. Their “diet-heart hypothesis” has been that the more saturated fat an individual consumes, the higher the low-density lipoprotein (LDL) or “bad” cholesterol raises, and so does the individual's risk for hypertension, cardiovascular disease, and stroke.
Since 1980, it has been recommended by all three organizations that saturated fatty acid intake be limited to less than 10% of total calories as a means of reducing the risk of cardiovascular disease.
This claim and recommendation is actually from the 1950s by Ancel Keys, who performed small feeding experiments on humans and some animal data suggesting high amounts of saturated fat lead to high blood cholesterol, creating fatty deposits that can lead to heart attacks. Unfortunately, these clinical trials do not support the statement that saturated fats cause heart-related diseases. In recent years, there has been a debate around saturated fats and heart-related diseases. Some studies state that there are correlations between saturated fat intake and and heart-related diseases, while others contradict the statement. Furthermore, in some studies, it’s found that certain foods containing saturated fats that are being consumed more regularly are what impact heart-related diseases.
With this, it has never been scientifically proven that high amounts of saturated fats are the cause of heart disease. While there may be a correlation between the two, we can’t dismiss other factors at play like smoking, lack of exercise, age, and family history.
Unsaturated Fats
Unsaturated fats are broken into two main groups: monounsaturated fats, which can be found in canola oil, olive oil, safflower oil, peanuts, peanut oil, peanut butter, almonds, almond butter, pecans, and pumpkin seeds; and polyunsaturated fats, which are where omega fatty acids are categorized.
Omega 3s and Omega 6s are the two main classes of polyunsaturated fats. Fatty fish such as salmon, herring, and sardines, as well as walnuts, flaxseeds, and sunflower seeds, are rich in Omega 3’s. Plant-based oils like safflower, grapeseed, flaxseed, sunflower, and soybean oil are rich in Omega 6’s.
You may have heard that unsaturated fats are considered the “healthy” type of fats and this is due to its impact of reducing LDL or “bad cholesterol.” Polyunsaturated fats are also beneficial for brain health, immune system, and reducing inflammation in the body.
There are 3 main types of Omega 3’s
eicosapentaenoic acid (EPA)
docosahexaenoic acid (DHA)
alpha-linolenic acid (ALA)
EPA and DHA are found mostly in fatty fish and ALA is found in flaxseed, chia seeds, walnuts, and canola oil.
Like saturated fats, Omega 6’s have gained popularity in recent years. The most common type of omega-6 is linoleic acid, which can be converted to arachidonic acid, a long-chain fatty acid, inside the body. Arachidonic acid produces eicosanoids, a pro-inflammatory hormone that is helpful for the immune system and aids in blood clotting and neurotransmission. Although high levels of eicosanoids can cause chronic inflammation, leading to health concerns, this is where controversy arises.
We do need some amounts of inflammation; we just don't want chronic inflammation. Studies have shown that the Western diet is exceeding the levels needed for omega-6's. We want a ratio of both omega 6 and omega 3 to be around 1:1 up to 4:1, but studies have shown that the current ratio is 15:1 to 16.7:1. Now, this is where controversy arises because people will take this and spin it to say that if we eat any foods high in omega 6's, then we are feeding inflammation and ruining our health.
If you’ve ever heard the “seed oils are terrible for you” statement, it's because the person is more likely to look at this through an all-or-nothing mentality. It’s not that we need to completely eliminate oils like safflower, sunflower, or soybean; it’s more so that we can begin adding in more omega-3 sources like fatty fish, olive oil, and avocados or oils.
What About Trans Fat?
Trans fat is a type of unsaturated fat that comes in two different forms: natural and artificial. Foods like meat and dairy contain naturally occurring trans fats and are considered safe to consume. Artificial trans fats, known as industrial trans fats, are formed from partially hydrogenated oils. This is when unsaturated fats (liquid at room temperature) are processed to become saturated (solid at room temperature) for reasons like a longer shelf life. There are both observational and cohort studies stating the impact that artificial or industrial trans fats have on health outcomes. Artificial or industrial trans fats have been linked to higher LDL “bad” cholesterol and lower HDL “good” cholesterol, which is associated with higher risks of coronary heart disease.
In 2018, the Food and Drug Administration (FDA) put into effect a ban on using hydrogenated oil in the most processed foods in the U.S. All manufacturers were to adhere to this final rule as of 2020. With this ban, it is still possible for very small amounts of trans fat to be found in food due to oils being at a high heat or when you cook with oils at a high temperature.
Artificial or industrial fats are mostly found in highly processed foods like fried foods (French fries, chicken, donuts), commercial baked goods, fast food, and frozen pizza.
My take on this is that you don’t want your entire diet to be made up of highly processed foods. You can take this nutrition information into account as well as be mindful of how your body feels, both physically and mentally, when making a food decision. Nutrition doesn’t need to be all or nothing. There is room for you to enjoy a slice of pizza or chicken nuggets without placing fear around these foods.
Benefits of Fats
Including sources of fat in your overall diet is essential to providing your body with energy, promoting cell functioning, and producing and maintaining hormones. Fats help to absorb other nutrients like fat-soluble vitamins A, D, E, and K and help to improve satiety by regulating appetite through mechanisms including the release of appetite hormones, inhibition of gastric emptying, and the amount of time it takes your body to break it down and release it.
More health benefits of eating adequate amounts of fat in your diet:
Lowering the risk of developing heart disease
Improving blood cholesterol levels
Balancing blood sugar
Lowering blood pressure
Improve gut health
Immune health
Brain and Eye development and health
Regulate metabolism
Skin, Hair, and Bone health
How Much Fat Should You Be Eating?
Fat requirements are very individualized and based on things like age, gender, physical activity, health conditions, etc., so again, this is why it’s important to work with a Registered Dietitian to determine your best needs.
However, for the general population, it is recommended that you receive anywhere from 20 to 35 percent of your total energy needs from dietary fat sources. For reference, if you were consuming roughly 2,000 calories, that represents 400–700 calories or around 45-75 grams of dietary fat. This method of calculating your fat needs is a bit stretched because everyone is super individualized, and you don’t necessarily need to count calories to know and understand what your body needs. Along with this total recommendation, it is also recommended that no more than 10 percent of dietary fat intake come from saturated fat sources. For reference, if you were consuming roughly 2,000 calories, that represents 200 calories, or around 20 grams of saturated fat.
If you’re not into calculating and keeping track of numbers (like me!), you can simply be mindful by incorporating around 1-2 servings of fat into most of your meals! This would be like 1 tablespoon of oil or butter, 1/3 of an avocado, or 2 tablespoons of peanut butter.
Again, keep in mind that everyone’s needs are different, and you may need more or less fat depending on your unique needs. This is why it’s important to work with a dietitian to help guide you.
Finding Your Balance with Fats
As you have read, dietary fats are essential to the diet, and you most certainly don’t need to fear adding fat to your meals and snacks. This is why I love educating you on nutrition so that you are equipped with the knowledge to make food decisions moving forward. We can look at nutrition, and in this case, fats, in a positive way while still getting to enjoy foods with different types of fat in them.
Looking back, we can take into account the controversial studies found with saturated fats and the clear findings of trans fats and keep in mind that nutrition isn’t all or nothing. We know that unsaturated fats are the most beneficial to the body and overall health, so using the phrase “for the most part” can be super helpful!
For the most part, choosing unsaturated fats like olive or canola oil, avocados, nuts and seeds, and fatty fish to include in your meals and snacks is a healthy choice. But, let’s not forget that finding satisfaction in your food is important too, so enjoying a buttered steak or a slice of chocolate cake can be a part of your feel-good journey!
Simple Ways to Add Fat
Incorporate unsaturated oils when cooking: olive, avocado, or canola
Pair a carbohydrate with a fat source for an energizing and balanced snack: crackers and cheese, apple and nut butter, or guacamole and chips
Top your yogurt parfait with chia seeds, hemp heart seeds, or flax seeds for some easy Omega’s
Add in 1-2 tablespoons of chia seeds to your morning oatmeal or overnight oats
Stock up on easy pantry staple fat sources like nuts and seeds, nut butters, dark chocolate, and canned fish like tuna and salmon
Spread avocado on your toast, sandwich, or wraps for additional fiber and monounsaturated fats
Go with full-fat dairy products to reap the benefits of the fats, calcium, vitamin D, and appetite regulation
Wrapping It Up
You don’t have to fear adding fat to your meals because it’s an essential nutrient for the body, adds flavor to food, and aids in absorbing other nutrients. Building a positive relationship with food doesn’t mean that you don’t care about how foods impact your overall health, so you can obtain nutrition knowledge and make intentional choices when it comes to dietary fats.
Using the phrase “for the most part” helps to continue that positive mindset while taking what we know from science about saturated fats, unsaturated fats, and trans fats so that you can optimize your health while still enjoying the fats you like.
Have questions? Leave them in the comments below!