The “nitty gritty” of how we lose weight!
This is probably the post you’ve been looking forward to! This is what our bodies do to break down the fat that is stored around our bodies and turns them into energy. In this post we will be discussing lipolysis and the factors that go into that process.
Let’s first start out by defining the building blocks of our fat stores!
The preferred source for our bodies energy needs comes from sugars. Sugars, whether simple or complex, get broken down into a molecule called glucose in which our bodies can either use for energy immediately or be stored for later use. When glucose gets stored in our bodies, our bodies combine multiple glucose molecules together to form a polymer called glycogen. Glycogen is the main building block for triacylglycerols (TAGs) which then get processed into the liver to form the building blocks for fat molecules that get stored in multiple sites in the body. To put this simply, and skipping a lot of steps/processes, dietary sugars get broken down, processed by the liver, and then are either used up immediately or stored as fat.
Let's dig deeper into what our bodies do to build those fat stores up!
The Liver is one of the most important organs that we have in our bodies. It is the location in which more than 500 identified processes occur that help our bodies maintain balance. Its main 4 functions include: Filtration, Digestion, Metabolism, and Detoxification. In this post we are just going to be focusing on what the liver does to help maintain our energy storage and consumption.
When digested sugars are broken down in our small intestine they travel in the bloodstream to the liver via insulin and then get modified into fats that then get stored in different areas of the body. You can think of insulin as a hormone that takes the free floating sugar in your bloodstream and brings it to the tissues that it needs in the body or to the liver for processing. We will be discussing insulin together at a later time as it is quite a broad subject to fit into this post.
Think of cholesterol as a transport mechanism for the sugars that have made their way to the liver. It moves the stored energy from one part of the body to another. Cholesterol is broken down into a few different categories. Chylomicrons, Very Low Density Lipoproteins (VLDLs), Low Density Lipoproteins (LDLs), Intermediate Density Lipoproteins (IDLs), and High Density Lipoproteins (HDLs). Each of these different types of cholesterol provide different functions. We’re going to be just touching upon what each of these do in terms that should be easy to understand. Chylomicrons are physically the largest of these lipoproteins and they are the primary transport protein for dietary fats, VLDLs are slightly smaller and transport triglycerides, LDLs also transport triglycerides but are more compact and are essentially more refined and are primarily transporting the stored energy into fat reserves, HDLs are the most compact form of cholesterol and functions to move energy from fat reserves to the liver to be processed into energy that the bodies can use. I want to emphasize that the definitions here for what these types of cholesterol do is very very simplified.
Let’s focus on the two main types of cholesterols that are most important when it comes to managing our weight: LDLs and HDLs. As mentioned in our previous paragraph LDLs are what moves energy into our tissues and HDLs are what move energy out from our tissues. We increase our amount of LDLs when we eat foods that are high in sugar and we increase our HDLs when we perform exercise (increasing our energy needs). In general terms, we want to keep our LDLs low and our HDLs high. There are many factors that go into maintaining our LDL/HDL ratios but the main two factors are our diets and our amount of exercise.
When our LDLs are high the body looks for places in which it can store that fat. Sometimes that fat is stored where we can see it, ie our belly, back, legs, love-handles, etc. and sometimes it's stored in places we can’t see like our liver, muscles, and our cardiovascular system.When our HDLs are high, the body takes the fat that is stored in various parts of our body and breaks them down via a process called Beta-Oxidation. This process involves breaking down the fat into multiple sub-components within our cell’s mitochondria where it gets transported into the citric acid cycle and then gets turned into energy. (Don’t worry I wont be explaining the citric acid cycle, we’ve all been scared about it enough at some point in our lives) This is the process in which our bodies are reducing fat. Some tidbits from this process that are very important are the requirements that are needed for this to happen.
At certain stages in breaking down the fat the body REQUIRES WATER to break down the bonds holding the fat together and produces CARBON DIOXIDE (CO2) and byproducts. Both are levers in which you pull in order to reduce the amount of fat that is stored inside your body. Firstly by drinking water you’re providing the body the ability to break down the fat, and by using your muscles/organs you’re producing carbon dioxide. The more you use the muscles the more energy your body requires, which increases the rate in which your body is using its HDLs to move fat from your storage sites into the mitochondria to be broken down which then produces carbon dioxide and byproducts that get either urinated or defecated out (peeing and pooping).
Now that we’ve touched upon how our bodies move around our energy, let’s discuss the factors that can either help build up or break down your energy stores. Some of these include Cortisol. Cortisol is a hormone created by your adrenal glands that are directly related to your autonomic nervous system. When your body is in a sympathetic state (fight or flight) it produces this hormone. Cortisol, during acute (short acting) phase, is what some refer to as a stress hormone and what it does is reduces the amount of fat in your liver and releases sugar into your bloodstream to provide the energy your body needs to either fight or run away from perceived danger. However cortisol, during a chronic state, has the opposite effect! It causes the body to maintain high levels of sugar in the bloodstream and causes you to hoard more fat inside your body. (again simplified)
Another hormone that plays its role in how your body processes its energy stores is norepinephrine. This hormone is responsible for a multitude of body processes but in a fasting state it triggers your fat stores to release glucose into the bloodstream to provide the energy that the body needs. You can have this hormone activate during your parasympathetic state (rest and digest) to reduce the amount of fat that your body holds onto.
When looking at changing your weight systematically we tend to gravitate towards looking for quick and reliable fixes that we can do to create the most amount of change. In reality, what we really need to focus on is what we’re doing long term. As a recurring theme in all of these articles suggest, we need to be focused on changing our habits. Changing them for the better, and making sure that we do that in ways that are attainable and sustainable.