The Importance and Benefits of Healthy Dietary Fats: A Functional Nutrition Perspective
In the world of nutrition, dietary fats have been given a bad reputation for decades. Well-known diet trends often point to fat as the culprit behind heart disease, weight gain, and a slew of health issues. However, from a Functional Nutrition viewpoint, fats are actually essential to our overall health, providing a range of benefits that support many aspects of our body's functioning. Rather than avoiding fat, it's important to understand the differences between the types of fats we consume and how healthful fats positively impact our blood sugar, heart health, digestion, metabolism, hormone health, and more. In this post, we'll dive deep into the history of why dietary fat was villainized, the role healthy dietary fats play in your body, their benefits, and how you can incorporate them into your diet.
The History of Dietary Fat
In the 80s and 90s, fat became a target of widespread vilification due to a combination of scientific studies, public health campaigns, and media influence. The belief that dietary fat was directly linked to obesity, heart disease, and other chronic health conditions led to the rise of promoting low-fat diets and fat-free food products. One key study was the Seven Countries Study conducted by Ancel Keys in the 1950s, which discovered a correlation between fat intake and heart disease. While the data was more nuanced than the outcome suggested, the idea was widely adopted by the public and health professionals. The U.S. government, influenced by these early studies, began recommending low-fat diets to improve heart health. The Dietary Guidelines for Americans emphasized reducing fat intake, especially saturated fat, which was believed to raise cholesterol levels and increase the risk of heart disease. In 1992, the USDA introduced the "Food Pyramid," which promoted a high intake of carbohydrates (mainly from poor-quality and refined grains) while encouraging the reduction of fat in the diet. As the public became more health-conscious, food companies took advantage of the growing fear of fat. This resulted in a surge of low-fat or fat-free versions of popular packaged foods, from snacks to dairy products to cookies. These products promised all the flavor and health benefits, with none of the "dangerous" fat.
Big Food Companies Ran with “Fat is Bad”
Food companies seized the opportunity to market "fat-free" and "low-fat" products to consumers as fat was demonized. The natural fats in foods were often replaced with sugar and refined carbohydrates to maintain flavor and texture. Big food companies used the low-fat narrative to their advantage:
Sugar Substitutes for Fat: Fat gives foods its flavor and texture, so without fat, food doesn't taste good. Companies needed a replacement for the missing fat, so they turned to sugar– high-fructose corn syrup, and artificial sweeteners make low-fat products taste more appealing. For instance, fat-free cookies, granola bars and yogurts were often loaded with sugar to compensate for the lack of fat. This resulted in foods that were lower in fat but higher in empty calories. Guess what happens when we eat excess processed sugar? The body turns the sugar into fat for storage through the process of lipogenesis, contributing to overeating, food cravings, weight gain and metabolic issues over time.
"Low-Fat" Processed Foods Emerge: Companies promoted “fat-free” or “low-fat” versions of traditionally high-fat foods—like ice cream, chips, condiments and salad dressings—despite these products containing large amounts of sugar, refined grains, and artificial ingredients. Marketing these products as “heart-healthy” or “diet-friendly” capitalized on the misconception that all dietary fat was inherently bad, while disguising the fact that these foods were becoming even more unhealthy due to their high sugar content.
Food Labels are Misleading: Many products were marketed with slogans like “No Fat!” or “90% Fat-Free!” but these labels failed to consider the product as whole, disregarding the high sugar content or the presence of other chemicals. Consumers felt like they were making healthier choices by purchasing fat-free items, without realizing that the reduction in fat was often offset by an increase in sugar and processed ingredients. The marketing strategy played on the fear of fat while offering a deceptive sense of healthfulness through sugar-laden products.
"Healthy" Junk Food Snackification: By the mid-90s, snack food manufacturers created “guilt-free” junk food items. For example, brands like Pringles, Lays and Go-Gurt introduced fat-free potato chips and yogurt, while snacks like “low-fat” granola bars and cereals became the go-to choices for people trying to lose weight. Despite being low in fat, these foods are high in refined carbohydrates, sugars, and preservatives. As a result, people consumed these products thinking they were making healthier decisions, when in reality, they were indulging in highly processed, nutrient-poor foods that created the internal systemic inflammation they were intending to prevent.
A False Dichotomy: The increase of low-fat foods also reinforced the false division between fat and sugar. Consumers were led to believe a product was automatically healthy if it was low in fat—regardless of other ingredients it contained. This allowed food companies to shift the focus away from the true causes of poor health, like an overall imbalance in the diet and eating artificial and processed sugars, and instead point the finger at fat as the primary enemy.
So, What are the Types of Dietary Fats?
Not all fats are the same– they are a diverse group of nutrients that come in different forms. Broadly, fats are categorized into three types: unsaturated fats, saturated fats, and trans fats.
Unsaturated fats: Considered as healthy fats, they are found in plant-based oils (like olive oil), nuts, seeds, avocados, and fatty fish. They can be further broken down into:
◦ Monounsaturated fats: These fats are abundant in olive oil, avocado, and nuts and seeds. They have been linked to reduced inflammation and improved heart health.
◦ Polyunsaturated fats: Found in fatty fish (salmon, mackerel), flaxseeds, and walnuts, these fats include omega-3 and omega-6 fatty acids, which are crucial for brain function, hormone regulation, and reducing inflammation. We want to have a 2:1 ratio of omega-3 to omega-6 fatty acids.
Saturated fats: Present in animal products like beef, eggs, chicken and dairy, as well as tropical oils like coconut oil. Saturated fats have been shown to play an important role in hormone production and cell membrane health. While moderation is key, current research has suggested that moderate intake of high-quality saturated fats may not be as harmful to heart health as previously thought.
Trans fats: These fats are artificially created through industrial processes and are found in many processed foods. Trans fats should be avoided at all costs. They are highly unstable, meaning they are more likely to oxidize when exposed to light and heat, causing increased inflammation, raising LDL cholesterol levels and triglycerides, and contributing to heart disease.
Why Dietary Fats Matter for Our Health
In addition to being a sustaining source of energy, fats play a crucial role in numerous physiological functions that contribute to overall health. Here’s a deeper look at how fats support various aspects of your well-being:
Absorption of Vitamins
Fats are essential for the absorption of fat-soluble vitamins–A, D, E and K. These vitamins are involved in key functions such as immunity, bone health, antioxidant protection and blood clotting. Without dietary fat, your body may struggle to absorb these vital nutrients, potentially leading to deficiencies that can impact overall health.
For optimal absorption, pair fat-rich foods like avocado, nuts, seeds, or olive oil with your meals, especially when you consume nutrient-dense vegetables such as spinach or kale.
Blood Sugar Balance
One of the most significant roles of healthy fats is in blood sugar regulation. Consuming fats alongside carbohydrates can help slow down the absorption of sugars into the bloodstream. This slower process keeps blood sugar levels stable, preventing the sharp spikes and crashes that can lead to energy dips, irritability, and long-term conditions such as insulin resistance and type 2 diabetes.
For example, adding a handful of nuts or a drizzle of olive oil to a carb-rich meal like roasted sweet potatoes or quinoa can help slow down the sugar absorption, stabilizing your blood sugar and keeping you energized for longer.
Digestive Health
Fats play a pivotal role in digestion, particularly in signaling for the gallbladder to release bile, which in turn helps with the absorption of dietary fats. In addition, healthy fats such as omega-3 fatty acids have anti-inflammatory properties that support a balanced gut environment, reducing inflammation in the digestive tract and promoting a healthy microbiome. A diet rich in healthy fats can be a game-changer for improving digestive health and ensuring proper nutrient absorption.
Hormone Balance
Hormonal health is deeply influenced by the types of fats we consume. Healthy fats are the building blocks for producing hormones, including sex hormones (estrogen, progesterone and testosterone) and adrenal hormones like cortisol. Without adequate fat intake, the body may struggle to produce these vital hormones, leading to imbalances that can affect everything from metabolism to mood and reproductive health.
The type of fats we consume also dictates either an anti-inflammatory or pro-inflammatory response. For example, omega-3 fatty acids, found in fatty fish like salmon and seeds like flax, are crucial for reducing inflammation and supporting the production of hormones. On the other hand, the omega-6 fatty acids found in processed vegetable oils, when consumed in excess, can promote inflammation, potentially leading to hormone imbalances.
Heart Health
The right kinds of fats are integral to heart health because fat is the heart muscle’s preferred source of energy. Contrary to the belief that all fats contribute to heart disease, the truth is that healthy fats such as monounsaturated fats and omega-3s can reduce the risk of heart disease by lowering LDL ("bad") cholesterol and raising HDL ("good") cholesterol. These fats help maintain the elasticity of blood vessels and reduce inflammation, both of which are crucial for cardiovascular health. Incorporating foods like avocado, olive oil, and fatty fish into your diet can significantly reduce the risk of heart disease and promote long-term cardiovascular health.
Cellular Health
Do you remember learning about the cell membrane in biology class? Well the membrane that protects the cell is made up of a mixture of saturated, monounsaturated and polyunsaturated fats. This includes the outer membrane and the membranes of your organs and tissues. Healthy fats are crucial for maintaining the integrity and fluidity of these membranes, ensuring that nutrients can be efficiently transported in and out of cells. If we eat unhealthy fats like trans fats, then the membrane becomes more rigid, making it harder for nutrients to enter and toxins to leave the cell. A diet rich in omega-3 fatty acids, found in foods like salmon, chia seeds, and walnuts, supports the healthy function of cell membranes, promoting efficient cellular communication and overall bodily function.
Satiety and Weight Management
Healthy fats play a key role in satiety, helping you feel full and satisfied after meals. I frequently use an analogy when working with clients that has to do with building a campfire. If we were to build a fire, we’d use some kindling to get the spark going, but if we only relied on kindling as a source of energy then the spark would quickly go out. We need to use logs on the fire for a long-lasting, sustainable burn. Carbohydrates are like the kindling, which can cause blood sugar spikes and crashes. Fats are like the logs, digesting more slowly, providing a lasting sense of fullness. This is especially helpful in sustaining energy throughout the day and managing weight, as fats help curb cravings and reduce the likelihood of overeating.
Including healthy fats in your meals—whether through a handful of nuts, a dollop of avocado, or a drizzle of olive oil—can promote satiety and help you maintain healthy eating habits, leading to better weight management in the long term.
Actionable Steps to Make Healthier Fat Swaps
Not all fats are created equal, and the choices you make can have a significant impact on your health. Here are some simple swaps to incorporate more healthy fats into your diet:
Opt for Organic: Swapping your conventional butter for grass-fed butter or ghee will provide you with a higher amount of omega-3 fatty acids. Fat stores toxins, so if the animal or oil was exposed to pesticides, antibiotics and other harmful chemicals that we don’t need in our food supply, they will be highly concentrated in the product.
Proper fat storage: Buy oils in glass bottles instead of plastic so the chemicals from the plastic are not leached into the oil. Keep your bottles of oil in a dark cabinet instead of near a window where they may get sunlight, or by the stove and oven where heat is emitted. This will prevent oxidation of the oils.
Replace vegetable oils with avocado, coconut or olive oil: Throw away the vegetable and canola oils. Read the ingredients that are in your PAM spray. Replacing these harmful oils with extra virgin olive oil, avocado and coconut oil are key.
Snack on nuts and seeds instead of chips: Nuts (like almonds, walnuts, or cashews) and seeds (like chia, flax, or pumpkin seeds) provide healthy fats, protein, and fiber, making them an excellent alternative to processed snacks that are high in trans fats, giving your body a greater nutritional value.
Add avocado to salads and sandwiches: Swapping out mayo that is made with soybean oil for a creamy shmear of avocado will taste great while providing your body with monounsaturated fats, which are great for your heart and skin.
Make homemade dressings: Dressing and condiments are a big culprit for unhealthy oils and sugars. Start making your own dressings using ingredients like olive oil, dijon mustard, balsamic vinegar and lemon juice. I promise you won’t want to go back to store bought dressings!
Use whole fat organic dairy: If you tolerate dairy, opt for whole-fat versions of milk, yogurt, and cheese. These foods provide beneficial saturated fats, which support cellular health and hormone production.
The Consequences of Low Fat Diets and Shift in Understanding
Fats are not the enemy. In fact, they are vital to our health and are an indispensable part of a well-rounded diet.
The low-fat movement contributed to an increase in the consumption of refined sugars and grains, and manufactured unhealthy fats like margarine and hydrogenated oils.These foods and chemicals led to weight gain, higher insulin levels, and increased risk for metabolic diseases like heart disease, type 2 diabetes and obesity. The focus has shifted from demonizing all fat as bad to focusing on the overall quality of fats. All fats are not harmful, and in fact, unsaturated fats and moderate amounts of saturated fat are necessary for our health. The body needs fat and is unable to make certain fats like omega 3 fatty acids on its own, meaning they must be obtained from diet. Without an adequate dietary fat intake someone is more likely to struggle with poor energy, increased cravings and hunger, impaired cellular health and detoxification, hormone imbalances, poor mental health– anxiety and depression, vitamin deficiencies, and weak skin, nails and hair. The key is to choose the right kinds of fats—unsaturated fats, omega-3 fatty acids, and moderate amounts of quality saturated fats—while avoiding unhealthy trans fats. Embracing fats as part of a balanced, nutrient-dense diet will not only improve your overall health but also ensure that your body has the fuel it needs to thrive. So, next time you’re planning a meal, don’t fear the fat—embrace it for better health and vitality.
References
Baranowski, T., O’Connor, T., Johnston, C., Hughes, S., Moreno, J., Chen, T. A., & Baranowski, J. (2017). School year versus summer differences in child weight gain: A narrative review. Childhood Obesity, 13(5), 1–12. https://doi.org/10.1089/chi.2017.0221
Harvard Health Publishing. (2019, August). The truth about fats: The good, the bad, and the in-between. Harvard Medical School. https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
Keys, A., Menotti, A., Aravanis, C., Blackburn, H., Djordevic, B. S., Buzina, R., Dontas, A. S., Fidanza, F., Karvonen, M. J., & Kimura, N. (1984). The seven countries study: 2,289 deaths in 15 years. Preventive medicine, 13(2), 141–154. https://doi.org/10.1016/0091-7435(84)90047-1
Mozaffarian, D., Katan, M. B., Ascherio, A., Stampfer, M. J., Willett, W. C., & Hu, F. B. (2009). Trans fatty acids and cardiovascular disease. New England Journal of Medicine, 360(15), 1601–1613. https://doi.org/10.1056/NEJMra0808500
Wu, Y., Zeng, J., Zhou, J., Li, P., Xu, H., Zhang, S., & Xie, H. (2022). Impact of dietary habits on gut microbiota and obesity: A review based on mechanism. Nutrients, 14(24), 5195. https://doi.org/10.3390/nu14245195
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