Why is fat the preferred fuel for the human body over glucose?
There are many arguments, especially those based around paleo diets, as to whether or no fat is the preferred fuel for the body over glucose. So, what is the difference between fat and glucose when it comes to our bodies fuel and energy levels and do our bodies prefer one over the other?
We depend on our daily food intake to replenish our daily fuel supply and the body requires this fuel in order to function at a normal rate. Our bodies fuel takes on three forms: Carbohydrates which are converted into glucose, fat, and protein. The body can also store some fuels in a form that offers our muscles an immediate supply of energy.
What is glucose and how do our bodies use it?
Glucose is derived from carbohydrates, such as sugar and starch, and is the bodies principle source of energy. Glucose can immediately be used as fuel for the body or it can be sent to other parts of the body, such as the liver and muscles, where it is stored as glycogen. The bodies liver can convert the glycogen back into glucose as well, but it is then directly released into the blood stream in order to maintain the bodies blood sugar level also known as blood glucose levels.
When you are exercising, your muscles pick up a portion of the glucose and use it as energy in addition to their glycogen
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As you exercise, stored fat in the body is broken down into fatty acids, which are then transferred through the blood to the muscles to be used as fuel. The process is however, slower than that of carbohydrates being broken down into fuel. During the process, fat is also stored within the muscles where it can be easily accessed during vigorous activity. Unlike the limited storage for glycogen, fat it virtually an unlimited supply of
Glucose consumption in the tissues and glucose production are balanced when the body is at rest. At the start of exercising the energy the body gets quickly is from the anaerobic metabolism using mostly muscle glycogen...
Animal metabolism consists of the utilization of nutrients absorbed from the digestive tract and their catabolism as fuel for energy or their conversion into substances of the body. Metabolism is a continuous process because the molecules and even most cells of the body have brief lifetimes and are constantly replaced, while tissue as a whole maintains its characteristic structure. This constant rebuilding process without a net change in the amount of a cell constituent is known as dynamic equilibrium (Grolier1996). In the combustion of food, oxygen is used and carbon dioxide is given off. The rate of oxygen consumption indicates the energy expenditure of an organism, or its metabolic rate (Grolier1996).
As Fink points out, Carbohydrates, in the form of glucose, are the main source of fuel for all physical activity. Fats on the other hand are primarily used as a fuel source while resting and when performing moderately to low intensity exercises. (Fink, 2012, p.3) It’s these facts that are so significant. The event she participates in will be fairly short yet very intense with that in mind as an 800-meter track athlete the Carbohydrates are going to serve her the best. She will require immediate as well as a short sustained use of energy for her event. While she will be using both energy systems Fink states she will mainly be using anaerobic energy system which “is a major contributor to intense activities that last from 1 to 3 minutes.” (Fink, 2012, p. 50)
The extra heat produced during metabolic exchange, raises the body temperature again affecting the enzymes and heat is then removed by sweating. If the body isn’t kept hydrated during exercise, dehydration will occur, causing the blood to become concentrated. When the blood becomes concentrated, the cells no longer have enough water to function.
In order for the body to maintain homeostatic levels of energy, blood glucose regulation is essential. Glucose is one of the body’s principal fuels. It is an energy-rich monosaccharide sugar that is broken down in our cells to produce adenosine triphosphate. In the small intestine, glucose is absorbed into the blood and travels to the liver via the hepatic portal vein. The hepatocytes absorb much of the glucose and convert it into glycogen, an insoluble polymer of glucose. Glycogen, which is stored in the liver and skeletal muscles, can easily be reconverted into glucose when blood-glucose levels fall. All of the body’s cells need to make energy but most can use other fuels such as lipids. Neurons; however, rely almost exclusively on glucose for their energy. This is why the maintenance of blood-glucose levels is essential for the proper functioning of the nervous system.
Glycemic index is the measure of how quickly blood glucose rise after eating a particular kind of food. This is used by estimating the how much each gram of carbohydrate consumed raises a person’s glucose level. During intense exercise, the body uses glucose as energy source before it starts relying of fats. “Prolonged exercise can only be continued when there is an adequate amount of carbohydrate available to fuel muscle and the brain”(William,2004). This shows that the amount of carbohydrate/glucose that is found within the body’s tissue has a significant amount of influence to play on how effective the early hours of an exercise would be. Glycemic index helps one to know how effective the carbohydrate/glucose within the body is functioning during exercise.
Tremblay, A., Simoneau, J., & Bouchard, C. (1994). Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism, 43(7), 814--818.
The postabsorptive state is the period when the GI tract is empty and energy comes from the breakdpwn of our body’s reserves. The importance of the postabsorptive state is to maintain blood glucose levels. The brain fuels itself using glucose as its energy source. We can get glucose from stored glycogen, tissue proteins, and some from fats. The first available store of glucose is in the liver’s stores of glycogen. These stores can maintain blood sugar levels for around four hours. When the liver stores begin to get small, glycogenolysis begins to take place in skeletal muscles. The glucose in the skeletal muscles is converted to pyruvic acid, which enters the blood and is converted back to glucose by the liver and again reenters the blood.
Our body needs energy to carry out its functions properly. This energy is synthesized from the food we eat. Our body breaks down the food we take in and then build up the required materials for a healthy functioning of our body. Glucose, a simple sugar or monosaccharide that is the end product of carbohydrate digestion, is a primary source of energy for living things. (Taber’s, 2005). Glucose gets absorbed from our intestines and distributed by the bloodstream to all of the cells in our body. If the supply of glucose is more than required, our body stores the excess amount of glucose as glycogen, a chain of glucose. If there is shortage in other hand, our body uses the stored...
Compare and Contrast Low Carbohydrate Diets and Low Fat Diets The two most popular methods to lose weight are the low carbohydrate diets and the low fat diets. Both are in complete contrast when it comes to each diet’s food choices, the low carbohydrate diet which completely breaks the food pyramid limits a person to eating foods that are high in carbohydrates, such as bread, pasta and rice, while on the other hand, the low fat diet which follow the food pyramid limits a person to eat foods that are high in fat like meat, milk, and bean groups. Although each diet may sound very different from one another, they also share similarities. Both the low carbohydrate diet and the low fat diet claim that each is a good tool for weight loss.
Our metabolism, “the totality of an organism’s chemical reactions”, manages energy usage and production of cells. We use energy constantly and our metabolism breaks down food through complex chemical reactions into energy our cells
Blood glucose levels are the measurement of glucose in an individual’s blood. This is important because glucose is the body’s main source of fuel and the brains only source of fuel. Without energy from glucose the cells would die. Glucose homeostasis is primarily controlled in the liver, muscle, and fat where it stored as glycogen. The pancreas is also a significant organ that deals with glucose. The pancreas helps regulate blood glucose levels. Alpha-islet and beta-islet pancreatic cells measure blood glucose levels and they also regulate hormone release. Alpha cells produce glucagon and beta cells produce insulin. The body releases insulin in response to elevated blood glucose levels to allow the glucose inside of cells and
Diabetes mellitus refers to a group of diseases that affect how your body uses blood glucose, commonly called blood sugar. Glucose is vital to your health because it's an important source of energy for the cells that make up your muscles and tissues. Glucose comes from two different sources, your liver and food. It's also your brain's main source of fuel. Glucose is made and stored in the liver. When your blood sugar gets low then your liver will use the stored glucose to keep your blood sugar level normal. If you have diabetes it means you have too much glucose in your blood. This is where insulin comes in. Diabetes is a growing epidemic in America's many nutritional diseases. There are a few factors that can cause or increase a person's chance of getting diabetes. Poor nutritional choices are a big factor in the cause of diabetes. The sad part is the increase is happening to the young children and teenagers in America. I will talk about what diabetes is, the increase in diabetes and why it’s so high, the complications that follow the diagnosis, and how it can be treated or reduced with diet and exercise.
All carbohydrates are made up of units of sugar (also called saccharide units). Carbohydrates that contain only one sugar unit (monosaccharides) or two sugar units (disaccharides) are referred to as simple sugars. Simple sugars are sweet in taste and are broken down quickly in the body to release energy. Two of the most common monosaccharides are glucose and fructose. Glucose is the primary form of sugar stored in the human body for ener...