Simply put, I'm here to debunk the bullshit. Your body needs fat. Here's why...
Dietary healthy fats are an important nutritional component of a healthy eating pattern not only because they’re essential for providing our bodies with energy, building healthy cells, providing insulation to maintain core body temperature, and regulating hormones, but also because fat is required for the absorption of fat-soluble vitamins that boost immunity and maintain bone, eye, and skin health.
3 Types of Dietary Fat
Before we get down to the dirty details, it's important for me to specify the differences between the 3 types of dietary fats. The types of fat we consume are an integral part of the puzzle, so let's identify them.
1. Unsaturated Fat
Unsaturated fats are typically found in plant food sources and are usually liquid at room temperature. This source of fat has immense health benefits, including lowering cholesterol and reducing the risk of heart disease. Common food sources include olive and canola oil, avocados, fish, almonds, soybeans, and flaxseed.
2. Saturated Fat
Saturated fats are found primarily in animal sources like meat, egg yolks, yogurt, cheese, butter, and milk, and are typically solid at room temperature. Finding balance with saturated fat is key to overall health, since too much of this fat source can contribute to stress on the heart. This most certainly does not mean that we need to eliminate them all together, but rather incorporate them into our diets in moderation (roughly 5-10% of our daily caloric intake).
3. Trans Fat
Trans fatty acids are created (naturally or man-made) when an unsaturated fat is made into a solid. Trans fats, like saturated fats, should also be incorporated into our diets on a smaller scale due to their tendency to increase cholesterol and risk of heart disease. Let me repeat that we do not need to eliminate these foods, but rather enjoy them in moderation. We all need a doughnut sometimes...
5 Reasons We Need Fat
1. Crucial to Cognitive Abilities
When you consider that our brains are more than two-thirds fat, and that our brain cell membranes are made of Essential Fatty Acids (EFAs), it's easy to see that our cognitive abilities depend on adequate and quality fat intake. The metabolic demands of the brain are so great that, under resting conditions, it uses one of every three calories we consume. And this calorie requirement is absolute.
Without enough fat, our brains become foggy and slow. Ever tried studying for a test on an empty stomach? Without enough fuel, and the right kinds of it, our bodies cannot perform.
2. Our Hormones Depend On It
Fats are structural components of some of the most important substances in the body. For starters, when women adopt low-fat diets, their estrogen levels drop noticeably. When these levels drop too low, it will begin to impact her reproductive system, often times leading to amenorrhea (an abnormal absence of menstruation).
The same is true for testosterone production in men. All steroid hormones have a structural backbone of a 17-carbon fat molecule called "gonane", making them fat-soluble hormones. Because of this, it's been proven that inadequate levels of dietary fat are extremely detrimental to the production of testosterone.
Additionally, Omega-3 fats support thyroid hormone function, which is a hormone closely involved in body fat regulation. We've been told that eliminating fat from our diet will help us lose fat, but it's actually quite the opposite - low-fat diets result in low thyroid hormone production. So in simpler terms, you cannot lose fat unless you eat fat. Imagine that!
3. Vital to Eye, Skin, and Bone Health
Think of dietary fat in your body like oil in your car - it keeps everything running smoothly. For starters, each skin cell is surrounded by two layers of fat that make up the cell walls and is known as the phospholipid bilayer. This layer incorporates dietary fats and is key in giving the appearance of plump, healthy skin.
In addition to that, DHA is a critical part of retinal structure (DHA is a long-chain omega-3 fatty acid found mainly in fish). Its presence enhances the development of photoreceptors, which are specialized cells in the retina necessary for vision.
Lastly, fat is needed to aid in the absorption and transportation of key bone building vitamins such as Vitamin K, D, and A. These vitamins aid in calcium and magnesium absorption along with regulating calcification in the bone. It has been recommended that the following fat sources are the best for bone health: olive oil, avocado, nuts and seeds, fatty fish and omega-3 fatty acids.
4. It Gives Us Energy
Fat provides the highest concentration of energy of all the nutrients. Without it, long duration, low intensity exercise would be impossible. For any fellow marathon runners, the phrase "hitting the wall" is too real. This fatigue is a result of the body's depletion of glycogen, meaning that our bodies must now rely on fat to power us through the last few miles of the race. But even if you're not running marathons, fat is essential for accessing stored carbohydrate reserves in the body during high intensity exercise. So in simpler terms, we've gotta put fuel in the tank to make it run.
In addition, fats can be useful for protection and adding bulk in particular sports. It is essential for protection of vital organs in contact situations, or for adding power in a tackle. And if that's not enough, for any winter athletes or open-water swimmers, fat is essential to providing a layer of insulation to keep you warm in frigid temperatures.
5. Revs Metabolism
Eat fat, burn fat. Similar to what I mentioned above, healthy fats can actually help with increasing satiety and speeding up metabolism. These healthy fats (the ones that come from whole, unprocessed foods) called MCTs have an usual chemical structure that allows the body to digest them more easily, turning them into fuel rather than storing them. MCTs can stimulate high metabolic rates, thyroid function, and energy production. They can be found in coconut oil and palm oil, and to a small degree, dairy products.
How Much Fat Should I Eat?
In short, our bodies need fat to function properly, and without a sufficient intake, many of our body's processes would fail. But now I'm sure you're wondering the big question...how much should I be eating?
The short answer is IT DEPENDS. The appropriate amount of fat to eat will depend on your calorie requirements, activity level, and lifestyle. The American Heart Association suggests that dietary fat should fall within the range of 20-35% of total daily calories for average adults, but let me repeat that this is a general recommendation, and your needs may be different.
If you are seeking to find out how much dietary fat your body requires, I highly recommend consulting your physician. While the internet is flooded with macro-nutrient calculators, those options are typically flawed. Determining your body's needs requires MUCH more than entering your height, weight and activity level. So instead of getting fed false information, go straight to the source.