Why we need fat
Simply put, fat is essential to the proper function of our hormones, our immune system, and our cells. It is the main building block in the production of each and every hormone in our body. This is so important! Hormones are key messengers that control our mood, energy levels, brain function, appetite, satiety, stress response, balance organ function, inflammation, immune function, and repair signals all across the body.
In addition, fats make up the walls of every cell in our body. We have trillions of cells in our bodies. Our cells are constantly taking in nutrients and sending waste and other products out for use in organs and systems around the entire body. Our cell walls need the right make-up of fats (including saturated fats and cholesterol) to surround and protect and for the cells to work as they are intended - to communicate with other cells, package up the products they are making, and send them to other parts of the body. The make-up of the cell walls reflects the quality and types of fats you are eating in your diet right now (and over the past few years). Eating nutrient-dense fats directly translates to our cells working more efficiently and effectively.
Fat also protects our organs and tissue from trauma and injury. It acts like a shock absorber. When we live a stressful lifestyle our body thinks that we are unsafe and sends out cortisol (one of our main stress hormones). Cortisol tells the body to store extra fat around our trunk, where our most important organs are located. This is why we often gain weight in the middle as we age (and experience more stress) and it can be hard to lose as long as we continue to experience stress in our lives.
Lastly, fat makes our food taste better and is also very satiating. Adding butter to a sweet potato, bacon to Brussel sprouts or a yummy dressing to a salad goes a long way in making these foods taste great. Fat provides flavor, aroma, and texture that make our food more pleasurable to eat. It also helps to make us feel full. Because fat is energy-rich (it contains more calories than the same amounts of protein or carbs) it can help make you feel more full while you are eating and for many hours after. Fat is like the slow-burning log in the fire, giving sustained energy, unlike carbohydrates which are more like kindling and burn more quickly. Just like for a fire, we need both!
Cholesterol isn’t bad
It is important that I touch on the critical topic of cholesterol when I write about fat. Cholesterol is a key ingredient in the structure of all of our cells and is also needed to create bile in our gallbladder which is key to breaking down and absorbing all of the fat we eat. when the body is not utilizing the fat we eat it can lead to deficiencies which can cause hormonal issues, musculoskeletal issues, cardiovascular issues, immune issues, allergies, skin problems, and even depression and anxiety. It is critical for newborn brain development (it is one of the main ingredients in breast milk), cognitive function, and memory throughout our lives. It is required in our skin cells to produce vitamin D when we are exposed to sunlight. It also helps keep the intestinal wall strong and flexible helping to protect our gut from becoming leaky.
The body produces 75% or so of the cholesterol in circulation throughout the body and 25% or so is utilized by the food we eat. The different forms of cholesterol like HDL (high-density lipoproteins) and LDL (low-density lipoproteins) are neither good nor bad. Both HDL and LDL are transporters that move cholesterol around. They are transport proteins that carry cholesterol around the body to where it is needed. LDL carries cholesterol around the body in one direction, back toward the tissues, and HDL carries cholesterol around the body in the other direction, away from the tissues. They are brought in to repair problems caused by high levels of inflammation and toxicity. They might repair a weakened arterial wall, smooth over an inflamed area or help bridge a path for immune cells to come in if needed.
Because cholesterol is utilized more often when there is a problem, having high or low levels of one or both types can be a sign of something bigger going on like blood sugar issues, digestive dysfunction, dysbiosis, poor diet, high-stress lifestyle, environmental toxins, chronic infection, and vitamin and mineral deficiencies.
High (or low) cholesterol is a signal or indicator of something else going on and is not a diagnosis on its own.
Types of fat
There are three main types of dietary fats: saturated, monounsaturated, and polyunsaturated. While we’ve been taught that animal products contain saturated fats and plant-based products contain unsaturated, this is inaccurate. Whole foods that contain fat contain ALL three types of fat, just in different ratios. Assuming we are consuming all of these types of fats, they all make up the walls of the cells in our bodies.
Saturated fat is abundant in foods like butter, coconut oil, eggs, and meat. The molecules in saturated fats do not contain double bonds and are packed more tightly together, which is what makes them solid at room temperature. Saturated fats are what give our cell walls their solid structure. Saturated fats make some of the best cooking fats because they hold up to higher heat, and do not go rancid as quickly as more delicate fats.
Monounsaturated fats are commonly found in olive oil, avocados, nuts like almonds and walnuts as well as seeds like pumpkin and sesame. Monounsaturated fats are more delicate than saturated fats, and more prone to oxidation and damage when exposed to high heat. They can also go rancid easily, which is why olive and avocado oils are typically stored in dark glass bottles. Unsaturated fats like monosaturated fats, give our cell walls the flexibility they need for nutrients to flow in and waste can flow out. These fats tend to perform best when cooked at moderate temperatures and can also be enjoyed at room temperature.
Polyunsaturated fats are found in high concentrations in foods like fish, nuts, and seed oils like soybean, sunflower, canola, and flax. Like monounsaturated fats, these fats are always liquid at room temperature and are the most delicate of all the fats. They can go rancid easily so it is best to consume most of these fats in their whole food form. Nuts and seeds are super nutrient-dense, but converting them to oil form is a challenging process that involves an incredible amount of processing that makes them free of color and flavor (making them appealing for processed/packaged foods and restaurants), but also highly toxic.
Harsh, petroleum-based chemicals are used during the processing of these industrial seed oils to bring them to a consumable form and to extend their shelf life. They end up toxic and inflammatory to the human body, especially when heated, as they degrade and release volatile toxic compounds into the air and our food. They are also challenging for our body to break down and absorb given their structure and lack of nutrients leading to lower stomach acid production and a higher chance of gas, bloating, and overgrowth of unwanted bacteria and fungus in the gut. Long-term overconsumption of these oils is linked to heart disease, diabetes, digestive distress, kidney and liver issues, cancer, neurological problems, and more.
These days most of us are aware of hydrogenated oils or trans fats, but you may not be aware that they are artificial versions of polyunsaturated fats like canola and soybean oil (and other vegetable oils) that are chemically altered to stay solid at room temperature, which gives them a longer shelf life, similar to vegetable oils like soybean and canola. These artificial fats are toxic to humans and are known to increase inflammation in the body and cause all sorts of health problems. These fats are predominately found in processed foods though they are becoming less abundant in the food supply today.
The right kinds of fats
Fat is a natural delicious food that has nourished humans for thousands of years. Good fats are fully intact and have not been altered with high heat or pressure. They are not rancid or oxidized and are naturally shelf-stable for some time. They typically come from whole-food sources and contain active “live” nutrients and enzymes.
All of the types of fats listed above (outside of the vegetable oils and trans fats) are great, nutrient-dense sources of fat. Whole food sources from animal products, avocados, and nuts and seeds are all great options and when it comes to oils my guidance is usually sticking with avocado oil, coconut oil, or ghee for cooking at higher heats and using extra-virgin olive oil, sesame oil and butter at low-moderate heat.
If you eat out regularly, it can be challenging to reduce or eliminate your exposure to industrial seed oils, but I suggest just doing the best you can to consume more nutrient-dense oils at home and as often as possible when eating out. The same thing goes for processed foods. The more you are able to cook your own food and snacks, the less exposure you will have to industrial seed oils.
How much fat should I eat?
How much fat you should eat depends on a number of factors including your age, activity levels, and overall health picture. Generally, the older you get, the more fat (and protein!) you require and the fewer carbs, but this isn’t the case for everyone. Overall you should be eating a balance of all of the macronutrients including protein and carbs. I generally recommend around 1-2 tablespoons per meal as a starting place. This is taking into consideration the fat within the other macronutrients you are eating in that meal also.
If you are working on your energy and mood via balancing your blood sugar, working on getting your hormones back into balance, or are recovering from an injury or surgery, you may want to consider increasing your fat for some time and reducing carbs. If you are hungry within an hour after eating meals it also might be good to examine how much fat you are eating and increase it a bit to help increase satiety. If you are not satiated after meals, have consistent energy throughout the day, recover well from workouts, have balanced hormones, struggle with brain fog, sleep and fatigue it might be worth changing up your fat intake to see if you feel better with a higher or lower amount.
Sources:
Nutritional Therapy Association curriculum
https://chriskresser.com/the-diet-heart-myth-cholesterol-and-saturated-fat-are-not-the-enemy/
https://www.healthline.com/nutrition/why-trans-fats-are-bad#blood-vessels-and-cancer
https://chriskresser.com/how-industrial-seed-oils-are-making-us-sick/