In order to understand the power our body fat holds, we need to reframe our understanding of body fat and come to appreciate its functions. We need to move away from the stigma and negative connotation that having fat on your body is inherently bad and relearn the purpose of why our bodies produce it in the first place. As a living, breathing, and moving organism, we are comprised of millions and millions of cells that make up our bones, muscles, organs, and yes, fat tissues. Therefore, it is helpful to view our fat or "adipose tissue" as more of a living organ with useful and critical functions rather than an unsightly addition to our hips and waists.
Let's take a look at some of the important functions our body fat and, more specifically, fat cells perform. First, and most obvious to the eye is insulation, cushioning, and temperature regulation. Thanks to the invention of clothing and fleece jackets, we no longer require excess body fat in times of extreme cold, however, our ancestors relied on the body's ability to store fat in order to make it through harsh winter climates. Further, body fat cushions our organs and bones naturally against outside physical harm. Next, in metabolically healthy individuals, white and brown adipose tissues secrete endocrine factors that maintain organ functions and metabolic homeostasis. Through these endocrine actions, these factors contribute to systemic energy metabolism by regulating appetite, thermogenesis, glucose metabolism, and lipid metabolism. These functions are critical for balancing hormones and regulating bodily functions. Lastly, and the function that I would like to focus on in this post is adipose tissue's function as a repository for stored energy. Energy storage in an environment of scarcity is critical for survival and the one evolutionary function that in today's abundant food environment might be unnecessary, however, it remains biologically available and active. Once we come to understand the levers that regulate this storage mechanism, we should be able to appreciate and control when and how much we store.
We have discussed the role of insulin and glucose with regard to fat storage in prior blog posts which focuses primarily on the metabolism of carbohydrates and sugar. In summary, carbohydrates are ingested, converted to sugar, blood sugar (glucose) rises, insulin is released to shuttle the glucose to the liver, muscles, or fat in order to remove from the bloodstream. The amount of available storage at each of these sites determine where the glucose ends up. We highlighted that if the liver and muscles are full, the body will store excess glucose in the fat cells with no maximum capacity. Thus, many would suggest in order to prevent glucose storage in the fat cells and weight gain, simply cut out refined carbohydrates and sugar from your diet in order to minimize the glucose spikes. Also, layer on some exercise to open up storage in the liver and muscles. This is a convenient way to view the insulin model of obesity; however, it is only half the story. What if you did implement a low carbohydrate diet and some exercise but were unable to see a reduction in adipose tissue? There must be a missing link. Most often in these situations, additional misguided advice that either, the carbohydrates are still too high allowing the body to use dietary (from food) carbohydrates from fuel or you're not exercising enough will be given. What if I told you there was an alternative answer and that understanding metabolism at the fat cell is the key to unlocking it. Well, I have good news, we need to talk about the other half of the equation.
Today's society, and honestly, myself included, have fallen for the victimization of carbohydrates and sugar due to their insulinogenic effects. We have placed them all in the "bad" bucket and even tried putting them on a spectrum of less bad to really bad by using glycemic indexes. As discussed in my CGM post, we can most certainly say that the glycemic index is incredibly unreliable as glucose responses can vary from person to person and even in the same individual for the same food, based on many variables such as activity level, sleep, stress, or even mealtime. Thus, I have concluded that declaring that carbohydrates as "bad" or concluding that they cause weight gain simply because they spike glucose and induce insulin secretion is a bit oversimplified. I can, however, get on board with the theory that chronically elevated glucose spikes do cause the formation of insulin resistance and will lead down the path to disease. Obesity usually is a symptom of this disease as a result of liver and muscle glycogen stores always being full due to lack of exercise or activity. Thus causing all the excess glucose to be stored in the adipose tissue causing weight gain. Ok, enough about carbs, what is the other half? We need to talk about the metabolism of fat.
Dietary fat has been vilified in the same vein as carbohydrates, however, instead of being blamed as a cause for weight gain, fat has been pegged as the leading cause of heart disease. This is an ongoing debate and outside the scope of this post, but again, I believe we have made an incredibly harmful assumption with this conclusion. There are many nuances and rabbit holes we can go down in regard to dietary fat, but I want to keep this simplified for purposes of how dietary fat affects the storage mechanism of our fat cells. Understanding the fat cells is critical to the missing link I have hinted at above. If we are able to grasp what turns on and off the storage mechanism at the level of the fat cell, we can unlock the ability to determine whether we are in energy storage or energy utilization mode.
As stated before, adipose tissue is a reservoir for energy. It holds thousands of calories of energy in the form of fatty acids (triglycerides) that can be released into the bloodstream for use. However, the problem is that many of us have locked up this ability to release the stored amounts by chronically shifting our cells into storage mode. However, once we unlock this mechanism, we can put our body fat to work, open up the fat cells to release their stored energy, and shrink the size of our adipose tissue. Much like the carbohydrate theory discussed above, insulin is the key driver as to whether our fat cells store or refuse to store excess energy. Insulin is the hormone that tells cells to open up for the ingestion of glucose in the form of triglycerides, thus, if we can get the fat cells to turn away insulin or become insulin resistant, then we can cut off the storage signal at the source. Pretty neat, but how?
We need to talk about the power plant of the fat cell, the mitochondria.
Without diving too deep, think of the mitochondria as the fat cell battery or power plant. In order for it to produce power, it needs to take in molecules from the food we ingest and turn them into adenosine triphosphate (ATP). ATP is an organic compound that gives all living organisms life and energy. The mitochondria will take in the fat from foods that we eat, convert it to ATP, and, depending on the type of fat that is ingested, will either leave on the fat storage switch on or turn it off. The key is to understand which fats can flip the switch off and cause the fat cell to become insulin resistant, thus stopping the storage of energy.
There are three types of fats; saturated, monounsaturated, and polyunsaturated that are metabolized similarly but result in different signaling once ATP is produced. The mechanism behind this is incredibly scientific and interesting, but I will spare you the details. Good thing is that studies have been done on different fat types and their metabolisms which have conclusively found that longer chain saturated fats have the highest capability, when metabolized, to flip the storage switch off at the fat cells signaling to the rest of the body that they are satiated and will no longer store energy. It isn't surprising that the foods highest in saturated fats come from the most satiating and nutrient-dense sources, animal-based products. Primary sources include red meat (beef, lamb, pork), whole-fat dairy products (milk, cream, cheese), butter, and lard. Think about the last time you ate a large amount of these foods. You probably left the table with an increased feeling of satiation and fullness. This is the mechanism at work!
So, if we can accept this theory and appreciate the power of saturated fat, we can then see how our food and dietary guidelines have set us up for absolute failure. Ever since the demonization of saturated fat in the 1960s and 70s, we have been told to stay away from these foods in order to protect ourselves from heart disease. Despite conforming to these guidelines as shown by a drastic reduction in red meat and milk products since publication, we have seen the highest rates of obesity and cardiovascular disease of all time. Could we have been unintentionally misled and literally left the door open for the unlimited storage of energy in our fat cells due to this misguided information? Given today's landscape of 88% of Americans being metabolically unhealthy, I would say the answer is a resounding, yes.
To add more fuel to the fire, our food industry has saturated (pun intended) the market with foods that contain large amounts of polyunsaturated fats or "PUFAs" in the form of refined seed and vegetable oils. Often, these oils are a byproduct of gasoline and animal feed production and go through an extensive extraction and processing process to make them bioavailable. The problem with these polyunsaturated oils is that they do not provide the same signaling when they are metabolized and in fact, leave the door to insulin open at the fat cell thus allowing for our fat cells to keep storing energy. When we eat these oils, our bodies never receive satiation signaling which is convenient for the processed food industry. Further, the metabolism of these oils in conjunction with sugar and refined carbohydrate, often found in processed foods, creates a perfect storm for elevated glucose, elevated insulin, and an open door to our fat cells primed to store all this excess energy in our adipose tissues. This powerful combination of sugar, carbohydrates, and PUFAs in the form of seed and vegetable oils, is the perfect concoction for maximal energy storage in our adipose tissue. It is no surprise then that when you look at the ingredient listing of many popular processed foods, salad dressings, cake mixes, chips, fries, bread, and many other items found in the food aisles of the grocery store, the first ingredients are typically sugar and vegetable oils (canola, corn, soybean, cottonseed, safflower, sunflower, etc). It is scary to think that the industry may have known about this science and did nothing, leading to our current environment of extreme rates of obesity and metabolic disease.
So what is next and how do we fix the damage?
On a personal level, in order to take advantage of this biological switch, it is in your best interest to pay attention to the types of fat in your diet. One must first work towards eliminating the sources of PUFAs in the form of refined seed oils. Unfortunately, this knocks out nearly all bagged and boxed "food products" found in the store as well as being extra careful to cooking methods used at restaurants and carry out locations as restaurants have substituted traditional use of butter and lard for these cheaper, reusable options. The next step would be towards ingesting more saturated fats in the form of animal products through cooking with lard and tallow, eating whole milk sources of dairy, and not being afraid of red meat. It is critical to maximizing your ratio of saturated fats to PUFAs to ensure proper metabolism and signaling at the fat cell level.
Recognizing this key difference in the metabolism of saturated fats vs polyunsaturated fats makes you appreciate how many cultures and past generations have been able to thrive on diets that comprised of high carbohydrates (Japanese/Chinese) or high fat (French/Inuit). It wasn't the inclusion of or lack of carbohydrates and sugar, it was the type of fat that was ingested alongside the carbohydrates. Unfortunately, Americans have gotten it wrong on both sides by refining carbohydrates and adding sugar to exorbitant amounts while eliminating saturated fats and substituting them with harmful PUFAs. Again, a recipe for chronically elevated blood sugar elevated insulin, and fat cells primed to store all the excess. Cookies, bread, cakes, sugar, rice, and pasta have been around for centuries; however, the astronomical consumption of refined vegetable oils is a recent phenomenon and just might be the root of our chronic disease and obesity epidemic. It is my hypothesis that eliminating these oils, maximizing animal-based saturated fat consumption, and limiting carbohydrates and sugar, in that order is the exact prescription we all need to unlock the power of our fat cells and stop the energy storage problem we are all facing.
I would certainly be remiss if I did not give credit where credit was due. I want to thank Paul Saladino, Dr. Mike Eades, and Brad Marshall for enlightening me on these theories and challenging my knowledge and landscape when it comes to new research in the health and wellness field. Here are some valuable articles and additional materials that take much more eloquent and deeper dives into the topics discussed.