Why You Need to Eat Fat to Burn Fat
The thought of eating fat still makes a lot of people cringe. For years, we have been told to eliminate fat from our diet for fear of weight gain, but the truth is, it hasn’t gotten us very far. Although we have been reaching for fat-free, low-fat and non-fat options, obesity rates continue to rise across North America, because the reality is that including fat in the diet is actually a good tool for weight loss. So, if you are still struggling to lose weight and afraid to add fat to your diet because you think it’s going to translate to body fat, let me help. Here is a case for fat, why you should include it in your diet, and why you need to eat fat to burn fat.
The Important Role of Fat
I have written at length about why fat doesn’t make you fat but if you are still struggling to understand this it’s really important that you try to wrap your head around this concept, otherwise it is going to hold you back from weight loss. Although dietary fat and body fat both share the word “fat” they are very different and have little in common. Dietary fat is one of the essential macronutrients in our diet and is vital for human health. Fats, in their natural food forms, are the building blocks for our hormones, brain and nerve tissues, protective layers of our cells, help to manage and control inflammation, and help us absorb vital nutrients including vitamin A, D, E and K. Dietary fats, in the form of triglycerides, cholesterol and essential fatty acids, help to insulate us, protect our vital organs, and are used as a source of stored energy.
Burning Fat vs. Carbs for Fuel
Much like a car, our bodies need fuel. We need fuel to get through our day and we need fuel for our vital bodily functions to occur. The human body has two primary sources of fuel; carbohydrates and fat. Carbohydrates (or glucose) are the body’s primary source of fuel, while fat is the body’s secondary source of energy, or backup fuel. What this means is that if both carbohydrates and fat are present, the body will use carbohydrates first, until they are no longer available, and then shift to burning fat for fuel. Think of it like a switch, as long as carbohydrates (or glucose) are present in the diet, your body will remain in a carbohydrate burning state, and then it will “flip the switch” and begin to burn fat for fuel. In a balanced state, the body should be able to naturally transition back and forth between using both carbohydrates and fat for fuel, however, (unfortunately) many people struggle to switch back and forth, which makes burning fat more difficult. Why? Because for many people the master controller of this switch, insulin, is no longer working as it should be.
Weight is about Hormones, not Fat
Insulin is a fat-storing hormone. Although that may sound like a bad thing, it is just doing it’s job. Every time that you eat food you trigger insulin, this tells the body to convert the food you’ve just eaten into stored energy, and once you finish eating, insulin then triggers the body to use the energy it stored. It is this process, of storing food as energy and then tapping into stored energy, that makes the human body efficient; you can eat a meal and then have energy stored for hours so you don’t need to constantly be looking for food. However, it is important to understand that the body stores energy for later in one simple form; fat. In fact, body fat is simply a form of stored energy that is present to protect us when we no longer have access to food. The problem? 1) In 2019, humans rarely go long periods of time without food, and 2) people do not allow their body to access this stored energy.
Control Insulin and Control Weight
The key to weight loss has less to do with calories, and a lot to do with insulin. Why? Because not all calories are created equal, and it is the quality of food that you eat, and macronutrient balance of it, that will determine how efficiently or inefficiently you will burn body fat.
Since insulin is what determines whether your body is storing fat or burning fat, to burn fat you need to make sure insulin is working the way it should. High insulin levels will keep your body in a fat storing state, while low insulin levels will allow your body to burn fat for energy. Of all of the macronutrients, it is carbohydrates, not fat or protein, that have the greatest impact on insulin. Every time that you consume carbohydrates you are triggering an insulin response. Therefore, by eating a diet high in carbohydrates, specifically refined carbohydrates and sugars, you train the body to use carbohydrates (or glucose) for fuel as opposed to fat. The more carbohydrates you eat, the higher your blood sugar, therefore the higher your insulin levels, and therefore the more you will store them as body fat.
Given the body will always prioritize using carbohydrates for fuel over fat, if you continue to eat carbohydrates you will never allow your body to actually transfer the fat that it has stored back into energy. Over time, it becomes more and more difficult for you body to transfer it’s stored fat to energy, because you become more and more insulin resistant, so your body thinks it needs more and more carbohydrates (i.e. sugar cravings), but only because it is so inefficient at converting stored fat back to energy. Depending on how resistant your insulin is (meaning how high your insulin levels are and how responsive your cells are to insulin), even consuming whole food forms of carbohydrates can make burning fat for fuel very difficult. For instance, a diet of oatmeal for breakfast, potato soup for lunch, and risotto for dinner can make burning fat for fuel almost impossible for someone with insulin resistance or someone who has been overweight for a long period of time, because the carbohydrate load is simply too high.
Why You Need to Eat Fat to Burn Fat
In order to address insulin resistance and transfer the body into a fat burning state it is vital that fat be included in the diet. Not only is fat vital for general health, but it does not trigger insulin the same way that carbohydrates, glucose or sugar do. Without fat, the body will continue to use and crave carbohydrates for fuel and never “flip the switch” to convert stored fat back to energy, so it will never have the opportunity to burn body fat. Not only does fat not trigger insulin the same way that carbohydrates do, but fat helps to manage our hunger cues, enabling us to eat less over time.
Because fat is very energy dense (i.e. a lot of energy in a small spoonful), it helps to keep us fuller for longer periods of time; manages our leptin and ghrelin, which are the gatekeepers of our appetite; and keep our cravings at bay by helping to balancing our blood sugar. By adding more fat to your diet you are also able to go longer periods of time between meals which further supports burning fat / weight loss since you force your body to use fat for fuel during these time periods. By eating meals that are high in fat, and moderate in carbohydrates, you are able to “flip the switch” from using carbs for fuel to fat for fuel more quickly, which keeps you in a fat burning state for longer periods of time.
A Fat Word of Caution
Although it is important to include fat in your diet, it is also important to understand that not all forms of fat are created equal. My suggestion to include fat in your diet is not permission to reach for deep fried foods, processed food and vegetable oils. If you want to use fat for fuel you need to focus on whole food forms of fat. Not only do processed forms of fat often come with added sugars (such as pre-made dressings and sauces), which will take you out of a fat burning state, but they are often made with refined forms of fat and vegetable oils which support inflammation, not weight loss. Instead, opt for natural cooking oils, such as butter, olive oil, coconut oil, and avocado oil, high-quality animal meats, high-quality dairy, whole eggs, seafood, nuts, seeds, olives and avocados.
The Bottom Line
Including fat in the diet is vitally important for weight loss, especially for the long-term, and choosing high-quality whole foods sources is just as important. When it comes to weight loss, carbohydrates are more troublesome than fat. That is not to say you can’t eat carbohydrates, but quality always trumps quantity, and for most people reducing their intake of refined carbohydrate and increasing their fat intake is key to burning more fat.