Some people may be uncomfortable taking part in conversations about fat. The thought of eating fat and have it get stored in the body seems to leave many afraid of the consequences, and therefore, they try to cut as much fats as they can out of their diet. Now, in rare cases eliminating fats for a period of time is the right step to take, but not so for the majority, and the widespread fear of fat has people grouping all fats and fatty foods in a single morbid category. To clear up some misconception about fat, let’s start by exploring what happens to this important macronutrient when eaten.
The basic reason we consume food is for our body to receive a diverse array of micronutrients & macronutrients for survival and thriving. Micronutrients are vitamins and minerals while macronutrients include Proteins, Carbohydrates and Fats, all of which are essential to our diet, meaning we need to eat them to live. I will break down micro and macronutrients further in a future blog. At the moment, we only need to know that fats are a necessary, not optional, part of a healthy lifestyle. But what happens to it once it’s in our bodies?
Benefits of Fatty Acids
Listed below are a few functions of what healthy lipids (aka fat molecules & fatty acids) do for us when we consume them:
- provides a source of energy
- stores future supplies of energy
- plays a key role in the structure and healthy maintenance of every cell in the body
- facilitates proper transfer of electrical currents in our nervous system
- provides insulation for nerves, organs and our muscles
- supports the body’s utilization of proteins
- helps to store and utilize certain vitamins, known as fat-soluble nutrients, including vitamins A, D, K & E
But First, We Digest
The overall digestive process begins once we put food in our mouths. First, enzymes and acids in the mouth and stomach start breaking down chains of fatty acids in our food.
Fun (sidetrack) fat fact #1:
I recently recalled an interesting fact about our bodies’ complex fatty acid breakdown from the book ‘Fats that Heal, Fats that Kill’ by Udo Erasmus. In it, Erasmus explains that pancreatic enzymes, along with bile , lecithin and lipase from the liver and gallbladder dismantle triglycerides, phospholipids and cholesterol from their outsides, separate the fatty acids from the cholesterol so that each molecule is directed to their proper place for use in the intestinal lining. This process also makes sure chemical protein cells that may be present within food molecules do not get into the bloodstream. fat molecules are then put back together again. This intricate separation and repackaging process ensures our bodies do not have to defend against these toxins later, which can become very stressful for the body! 1
Most of the fat though is only metabolized once it reaches the small intestine. Fat molecules are broken down small enough to become absorbed through the wall of the small intestine and into the blood stream.
It’s not the destination, it’s the climb
Once in the blood stream, fatty acid molecules are packaged into ‘travel pouches’ so to speak, and directed to a vein near the heart, where they are distributed throughout our body, via the bloodstream.
From here, fats travel to the liver in new packages called High-density lipoproteins (HDL), eventually broken down into Low-density lipoproteins (LDL) for them to be properly absorbed by each of our cells.
At this point, the body’s trillions of cells take in as much LDL molecules from the fats as they can handle, and then shut down from receiving any more. Leftover fat molecules circulate through the bloodstream and either get processed by the liver, or become fat cells and stored as fuel for later.
This type of excess fat is stored around organs for quick access and doubles as insulation or protection of our organs.
Placement of fat around the core organs also ensures cholesterol fat is quickly transported to the liver to be further metabolized, so it may in turn help break down newly consumed fats, and get eliminated through the stool. This is a basic description of how most of our fats are digested and utilized in our bodies. There’s so much more to the story, but forgive me, I wanted to save a little energy…………….see what I did there?
Types of body fat
There are three types of fat stored in the body, essential, subcutaneous and visceral fat. Essential fat is the critical fat needed by our brain, nerves, bones and membranes, and is needed to survive. Subcutaneous fat is stored just under the skin, and its main function is to insulate and protect muscles and bones, energy storage and facilitates a passage for nerves and blood vessels to flow effectively through the body. Visceral fat exists much deeper in the body, surrounding vital organs including the intestinal tract. Visceral fat is considered damaging to health as it is associated with increased incidence of heart disease, high blood pressure, diabetes and high cholesterol. Belly fat falls in the category of visceral fat. According to a study done at Johns Hopkins University, an excess of visceral fat surrounding the liver can break down into cholesterol, breaking free into the bloodstream and collect in the arteries. 2 This is the beginning of atherosclerosis.
Let’s throw out the outdated concept that one type of fat is ‘bad’ and the other is ‘good’. A healthy amount of either is beneficial, but an excessive amount of either type of fat is not good. Too much subcutaneous fat can also contribute to heart disease, high blood pressure, sleep apnea, liver and kidney diseases. A modest amount of visceral fat insulates and protects the digestive tract and other organs. It is important to keep in mind however, that an excess of visceral fat, or belly fat, is considered a greater threat to health, if not immediately then in the future.
Let’s get a little closer to the deep end
Apart from the location of storage there are two main types of fat cells within these areas; white and brown fat cells. White fat cells (aka adipocytes), consisting mostly of fatty acids, are found in both subcutaneous & visceral fat, usually around the stomach, thighs and hips, building up as we consume calories and used as energy when the body is otherwise in short supply. Over accumulation of white cells tends to be from overeating and can lead to obesity.
Brown fat (aka brown adipose tissue) first develops in us as young infants, accumulating behind the shoulder blades, serving its main purpose to burn energy and keep us warm. We still have some of the brown fat we were born with, though much less than what we had as infants. Adults have less brown fat than white fat, but people who are lean keep more brown fat in their bodies than overweight or obese people do.
Fun (sidetrack) fat fact #2: newborns tend to not shiver when they’re cold! Babies are born with an abundance of brown fat, which provides them with heat instead. Shivering is the body’s way of creating warmth through friction within the body, but infants don’t need that friction. The burning of brown fat is activated by the baby’s hormones to create warmth on it’s own, a process called thermogenesis.
There is also evidence of a third type of fat cell called beige fat. Humans only seem to have about 0.1% body mass of beige fat, and it seems these cells used to be white fat cells that started to behave like the brown fat cells. The process called ‘browning’ seems to be aided by cold temperatures, healthy diet and exercise. Further information on this can be found here.
For years, studies have been exploring any possible benefits of brown adipose tissue other than thermogenesis.
One study from 2010 found here, used mice to demonstrate it is possible for the body to use brown adipose tissue as an energy burning method for weight loss. They found when they added brown adipose tissue to mice, their utilization of energy increased, and the total fat in their bodies was reduced. Brown fat was also studied with mice in relation to the Ketogenic diet, found here, showing that the diet was associated with increased accumulation of brown fat, higher energy expenditure, and potential weight loss.
Thermogenesis indicates our body’s ability to adapt to various surrounding conditions. As stated in Michael T. Murray’s book ‘The Encyclopedia of Natural Medicine‘, thermogenesis is the body’s process of creating heat by breaking down fat tissue for heat energy. How quickly our bodies can carry out this process is a good indicator of our bodies’ adaptability. It is believed that the effectiveness of thermogenesis varies, and that leaner people can initiate thermogenesis much easier because they have more brown fat. Another reason overweight and obese people have lower levels of thermogenesis is due to insulin resistance, meaning sugar from your bloodstream can not be ushered into the body’s cells effectively. Based on this theory, thermogenesis can be increased by enhancing insulin sensitivity, by doing things such as lowering stress, eating a lean diet high in fiber, whole fruits and vegetables, and replacing processed and refined foods with whole foods. This would assist the body to achieve normal thermogenesis, in other words, to burn more fat thus storing less.
Ok, so we may know that conditions like being overweight and, more severely, obesity, increases the risk for conditions such as heart disease, high blood pressure and even organ failure. What we may not all know are the varied and complex reasons that cause fat accumulation and obesity. This topic is detailed and elaborate, but I’ll try to sum it up here.
Though some of us may inherit genes that predispose us to obesity, the condition can still be sidestepped with good diet and lifestyle habits. Psychological factors have a great deal of influence on our diet and lifestyle. This can be to our detriment, such as our main example of the negative influence television. Watching TV while eating distracts us from chewing slowly and thoroughly, causing us to swallow our food too fast, and create unnecessary challenges for our digestive system. Television can also become a cue for hunger, with characters frequently eating, and so many advertisements for processed foods using visual tactics to encourage the sale of quick and delicious but nutritionally empty or unhealthy foods. People of all sizes tend to tune in to external hunger cues like sight, sound and smell, rather than internal cues, such as intuition, to cue and initiate and knowing when to stop eating. When it comes to TV and obesity, it is like the “chicken or the egg” discussion, and I wonder if television is not more the cause than effect.
The physiological theory contradicts this a bit by theorizing that obese individuals are actually extremely connected to the internal hunger cues, but they are stuck in a pattern that stimulates uncontrollable appetite. A major contributing factor may be the development of insulin resistance, often a result of the body’s long-term response to high sugar or carbohydrate diet. Obesity causes a vicious feedback cycle of insulin resistance, causing more abdominal obesity, as well as instigating negative altering of fat cell hormones, loss of appetite control, impaired thermogenesis and low brain serotonin. The brain chemical serotonin seems to play a role in making an eating habit become an eating disorder. In the future I may write a blog describing the effects of serotonin levels on obesity, but if you are interested I encourage you to look into that yourself in the meantime.
Either of these theories seem to have a good argument.
I hope this clarified how the body digests, metabolizes and stores fats we consume, and gave you a better understanding of how, where and why fat gets stored in our bodies. Fat does not have to be the enemy, in fact in many ways it’s our friend, and can contribute to our optimum health and homeostasis.
The simplest solution to contributing to healthy fat storage in our bodies is to just eat a healthy whole food diet, work on optimizing digestions and lowering stress levels. There are various ways of achieving each these goals, all depending on your individual strengths and weaknesses. A nutritionist is here to help guide you to a healthy lifestyle, and I would recommend speaking to one, such as myself if you want to explore this topic further, for your own optimal health
Stay healthy and happy all!
1: Fats That Heal, Fats That Kill by Udo Erasmus. Pg. 163-168
3 : The Encyclopedia of Natural Medicine by Michael T. Murray, N.D. & Joseph Pizzorno, N.D.