Teaching The Body To Use Fat As Primary Energy At Rest - Changing Body Composition.
Sugar in your food generally requires little to no digesting or processing and will be in your bloodstream inside 60 minutes after eating. In response, blood sugar shoots up for a bit before coming back down rapidly a short while later. Other carbohydrates, referred to as complex carbohydrates, will be sugar in your bloodstream as well eventually. It takes your digestive system a little longer to convert complex carbs into simple sugars, so blood sugar will rise and fall a bit slower depending on a few factors. These include the type of carbohydrate (how "complex" it is) and how fibrous and/or fatty the food is. Once in the blood, your metabolism begins to use sugar in a variety of ways. Particularly if you are active or exercising, some of the sugar in your blood will be used quickly for energy. Glucose and/or fructose are the end-products of all carbohydrate breakdown. These simple sugars enter into either glycolysis (for glucose) or fructolysis (for fructose). In these processes, the metabolism uses the simple sugars to generate the compounds that, in turn, power all of the body's other metabolic processes. Put more simply, glycolysis and fructolysis convert simple sugars into energy. (A quick note on fiber: fiber is classified as a type of carbohydrate and is listed on nutrition labels under the carbohydrate section. Most fiber will pass through the body undigested. The remainder will be digested quite slowly over the course of many hours. Fiber does not have a meaningful effect on blood sugar.) Most of the time, however, sugar is not used immediately but is stored in cells for use later. This is where insulin comes into the equation. Insulin is a protein that acts as a hormone in the digestive process. When a protein is classified as a hormone, it means that it's p Continue reading >>
Does Carbohydrate Become Body Fat?
Dear Reader, Ah, poor carbohydrates, maligned by diets such as Atkins’ and the ketogenic diet. However, carbohydrates are your body’s main source of energy — in fact your muscles and brain cells prefer carbs more than other sources of energy (triglycerides and fat, for example). To answer your question: research completed over the last several decades suggests that if you are eating a diet that is appropriate for your levels of daily activity, little to no carbohydrate is converted to fat in your body. For most people (unless you have a metabolic disorder) when you eat carbs they are digested, broken down to glucose, and then transported to all the cells in your body. They are then metabolized and used to support cellular processes. If you’re active and eating appropriately for your activity level, most of the carbs you consume are more or less burned immediately. There are two caveats here: first, if you’re eating a lot more calories per day than you are burning, then yes, your liver will convert excess calories from carbohydrate into fats; second, not all carbs are created equal. If you consume too many calories from simple sugars like sucrose and fructose (think sugary sodas sweetened by sugar and high fructose corn syrup) then your body will more readily take some of those sugars and turn them into triglycerides (fat) in your liver. What happens to excess calories that come from carbs? The answer depends on several things: what kind of carbs you consumed, your genetics, as well as how many extra calories we’re talking about. For those who eat a well-balanced diet and have no metabolic disorders, excess dietary carbohydrates are converted by the liver into complex chains of glucose called glycogen. Glycogen is stored in liver and muscle cells and is a sec Continue reading >>
Cell Energy And Cell Functions
Cells manage a wide range of functions in their tiny package — growing, moving, housekeeping, and so on — and most of those functions require energy. But how do cells get this energy in the first place? And how do they use it in the most efficient manner possible? Cells, like humans, cannot generate energy without locating a source in their environment. However, whereas humans search for substances like fossil fuels to power their homes and businesses, cells seek their energy in the form of food molecules or sunlight. In fact, the Sun is the ultimate source of energy for almost all cells, because photosynthetic prokaryotes, algae, and plant cells harness solar energy and use it to make the complex organic food molecules that other cells rely on for the energy required to sustain growth, metabolism, and reproduction (Figure 1). Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier — but not an impassable one. Like the exterior walls of a house, the plasma membrane is semi-permeable. In much the same way that doors and windows allow necessities to enter the house, various proteins that span the cell membrane permit specific molecules into the cell, although they may require some energy input to accomplish this task (Figure 2). Complex organic food molecules such as sugars, fats, and proteins are rich sources of energy for cells because much of the energy used to form these molecules is literally stored within the chemical bonds that hold them together. Scientists can measure the amount of energy stored in foods using a device called a bomb calorimeter. With this technique, food is placed inside the calorimeter and heated until it bu Continue reading >>
Absorbing And Storing Energy: How The Body Controls Glucose
Absorbing and Storing Energy: How the Body Controls Glucose Editors note: Physicians have a special place among the thinkers who have elaborated the argument for intelligent design. Perhaps thats because, more than evolutionary biologists, they are familiar with the challenges of maintaining a functioning complex system, the human body. With that in mind, Evolution News is delighted to offer this series, The Designed Body. For the complete series, see here . Dr. Glicksman practices palliative medicine for a hospice organization. Just like a car needs the energy, in the form of gasoline, to run properly, the body needs the energy in glucose to survive. When we havent eaten for a while, our blood glucose level drops and our stomach is empty, causing the hunger center in our brain to tell us to eat or drink something with calories. As I have explained in my last couple of articles, the complex molecules that are in what we eat and drink enter the gastrointestinal system, where digestive enzymes break them down into simpler molecules so the body can absorb them. Carbohydrates are broken down into simple sugars, like glucose, which are then absorbed into the blood. Tissues, such as the brain and other organs, rapidly absorb some of this glucose, to be used for their immediate energy needs. However, the amount of glucose absorbed after a meal is usually much more than what the tissues can use right away, causing excess. The body is able to chemically link these excess glucose molecules together to form a carbohydrate called glycogen. Most of the glycogen in the body is made and stored in the liver, with smaller amounts in the muscles, kidneys, and other tissues. Once the liver and other tissues have filled up their glycogen stores, any excess glucose is stored as fat, appare Continue reading >>
The Science Behind Fat Metabolism
Per the usual disclaimer, always consult with your doctor before experimenting with your diet (seriously, go see a doctor, get data from blood tests, etc.). Please feel free to comment below if you’re aware of anything that should be updated; I’d appreciate knowing and I’ll update the content quickly. My goal here is to help a scientifically curious audience know the basic story and where to dive in for further study. If I’m successful, the pros will say “duh”, and everyone else will be better informed about how this all works. [UPDATE: based on a ton a helpful feedback and questions on the content below, I’ve written up a separate article summarizing the science behind ketogenic (low-carb) diets. Check it out. Also, the below content has been updated and is still very much applicable to fat metabolism on various kinds of diets. Thanks, everyone!] tl;dr The concentration of glucose in your blood is the critical upstream switch that places your body into a “fat-storing” or “fat-burning” state. The metabolic efficiency of either state — and the time it takes to get into one from the other — depends on a large variety of factors such as food and drink volume and composition, vitamin and mineral balances, stress, hydration, liver and pancreas function, insulin sensitivity, exercise, mental health, and sleep. Carbohydrates you eat, with the exception of indigestible forms like most fibers, eventually become glucose in your blood. Assuming your metabolism is functioning normally, if the switch is on you will store fat. If the switch is off, you will burn fat. Therefore, all things being equal, “diets” are just ways of hacking your body into a sufficiently low-glycemic state to trigger the release of a variety of hormones that, in turn, result in Continue reading >>
How Sugar Makes You Fat
Look at how many grams of sugar are in what you’re eating (on the nutritional label). Now divide that number by 4. That’s how many teaspoons of pure sugar you’re consuming. Kinda scary, huh? Sugar makes you fat and fatfree food isn’t really free of fat. I’ve said it before in multiple articles, but occasionally, I’ve had someone lean over my desk and say “How in the heck does sugar make you fat if there’s no fat in it?”. This article will answer that puzzler, and provide you with some helpful suggestions to achieve not only weight loss success, but improved body health. First, let’s make some qualifications. Sugar isn’t inherently evil. Your body uses sugar to survive, and burns sugar to provide you with the energy necessary for life. Many truly healthy foods are actually broken down to sugar in the body – through the conversion of long and complex sugars called polysaccharides into short and simple sugars called monosaccharides, such as glucose. In additions to the breakdown products of fat and protein, glucose is a great energy source for your body. However, there are two ways that sugar can sabotage your body and cause fat storage. Excess glucose is the first problem, and it involves a very simple concept. Anytime you have filled your body with more fuel than it actually needs (and this is very easy to do when eating foods with high sugar content), your liver’s sugar storage capacity is exceeded. When the liver is maximally full, the excess sugar is converted by the liver into fatty acids (that’s right – fat!) and returned to the bloodstream, where is taken throughout your body and stored (that’s right – as fat!) wherever you tend to store adipose fat cells, including, but not limited to, the popular regions of the stomach, hips, but Continue reading >>
How Our Bodies Turn Food Into Energy
All parts of the body (muscles, brain, heart, and liver) need energy to work. This energy comes from the food we eat. Our bodies digest the food we eat by mixing it with fluids (acids and enzymes) in the stomach. When the stomach digests food, the carbohydrate (sugars and starches) in the food breaks down into another type of sugar, called glucose. The stomach and small intestines absorb the glucose and then release it into the bloodstream. Once in the bloodstream, glucose can be used immediately for energy or stored in our bodies, to be used later. However, our bodies need insulin in order to use or store glucose for energy. Without insulin, glucose stays in the bloodstream, keeping blood sugar levels high. Insulin is a hormone made by beta cells in the pancreas. Beta cells are very sensitive to the amount of glucose in the bloodstream. Normally beta cells check the blood's glucose level every few seconds and sense when they need to speed up or slow down the amount of insulin they're making and releasing. When someone eats something high in carbohydrates, like a piece of bread, the glucose level in the blood rises and the beta cells trigger the pancreas to release more insulin into the bloodstream. When insulin is released from the pancreas, it travels through the bloodstream to the body's cells and tells the cell doors to open up to let the glucose in. Once inside, the cells convert glucose into energy to use right then or store it to use later. As glucose moves from the bloodstream into the cells, blood sugar levels start to drop. The beta cells in the pancreas can tell this is happening, so they slow down the amount of insulin they're making. At the same time, the pancreas slows down the amount of insulin that it's releasing into the bloodstream. When this happens, Continue reading >>
Physiologic Effects Of Insulin
Stand on a streetcorner and ask people if they know what insulin is, and many will reply, "Doesn't it have something to do with blood sugar?" Indeed, that is correct, but such a response is a bit like saying "Mozart? Wasn't he some kind of a musician?" Insulin is a key player in the control of intermediary metabolism, and the big picture is that it organizes the use of fuels for either storage or oxidation. Through these activities, insulin has profound effects on both carbohydrate and lipid metabolism, and significant influences on protein and mineral metabolism. Consequently, derangements in insulin signalling have widespread and devastating effects on many organs and tissues. The Insulin Receptor and Mechanism of Action Like the receptors for other protein hormones, the receptor for insulin is embedded in the plasma membrane. The insulin receptor is composed of two alpha subunits and two beta subunits linked by disulfide bonds. The alpha chains are entirely extracellular and house insulin binding domains, while the linked beta chains penetrate through the plasma membrane. The insulin receptor is a tyrosine kinase. In other words, it functions as an enzyme that transfers phosphate groups from ATP to tyrosine residues on intracellular target proteins. Binding of insulin to the alpha subunits causes the beta subunits to phosphorylate themselves (autophosphorylation), thus activating the catalytic activity of the receptor. The activated receptor then phosphorylates a number of intracellular proteins, which in turn alters their activity, thereby generating a biological response. Several intracellular proteins have been identified as phosphorylation substrates for the insulin receptor, the best-studied of which is insulin receptor substrate 1 or IRS-1. When IRS-1 is activa Continue reading >>
What Is Glucose?
Glucose comes from the Greek word for "sweet." It's a type of sugar you get from foods you eat, and your body uses it for energy. As it travels through your bloodstream to your cells, it's called blood glucose or blood sugar. Insulin is a hormone that moves glucose from your blood into the cells for energy and storage. People with diabetes have higher-than-normal levels in their blood. Either they don't have enough insulin to move it through or their cells don't respond to insulin as well as they should. High blood glucose for a long period of time can damage your kidneys, eyes, and other organs. How Your Body Makes Glucose It mainly comes from foods rich in carbohydrates, like bread, potatoes, and fruit. As you eat, food travels down your esophagus to your stomach. There, acids and enzymes break it down into tiny pieces. During that process, glucose is released. It goes into your intestines where it's absorbed. From there, it passes into your bloodstream. Once in the blood, insulin helps glucose get to your cells. Energy and Storage Your body is designed to keep the level of glucose in your blood constant. Beta cells in your pancreas monitor your blood sugar level every few seconds. When your blood glucose rises after you eat, the beta cells release insulin into your bloodstream. Insulin acts like a key, unlocking muscle, fat, and liver cells so glucose can get inside them. Most of the cells in your body use glucose along with amino acids (the building blocks of protein) and fats for energy. But it's the main source of fuel for your brain. Nerve cells and chemical messengers there need it to help them process information. Without it, your brain wouldn't be able to work well. After your body has used the energy it needs, the leftover glucose is stored in little bundles Continue reading >>
When Does Glucose Convert To Fat?
Despite the fact that eating a jelly doughnut seems to deposit fat directly on your hips, converting sugar to fat is actually a relatively complex chemical process. Sugar conversion to fat storage depends not only upon the type of foods you eat, but how much energy your body needs at the time you eat it. Video of the Day Your body converts excess dietary glucose into fat through the process of fatty acid synthesis. Fatty acids are required in order for your body to function properly, playing particularly important roles in proper brain functioning. There are two kinds of fatty acids; essential fatty acids and nonessential fatty acids. Essential fatty acids refer to fatty acids you must eat from your diet, as your body cannot make them. Nonessential fatty acids are made through the process of fatty acid synthesis. Fatty Acid Synthesis Fatty acids are long organic compounds having an acid group at one end and a methyl group at the other end. The location of their first double bond dictates whether they are in the omega 3, 6, or 9 fatty acid family. Fatty acid synthesis takes place in the cytoplasm of cells and requires some energy input. In other words, your body actually has to expend some energy in order to store fat. Glucose is a six-carbon sugar molecule. Your body first converts this molecule into two three-carbon pyruvate molecules through the process of glycolysis and then into acetyl CoA. When your body requires immediate energy, acetyl CoA enters the Citric Acid Cycle creating energy molecules in the form of ATP. When glucose intake exceeds your body's energy needs--for example, you eat an ice-cream sundae and then go relax on the sofa for five hours--your body has no need to create more energy molecules. Therefore, acetyl CoA begins the process of fatty acid syn Continue reading >>
How Fat Cells Work
In the last section, we learned how fat in the body is broken down and rebuilt into chylomicrons, which enter the bloodstream by way of the lymphatic system. Chylomicrons do not last long in the bloodstream -- only about eight minutes -- because enzymes called lipoprotein lipases break the fats into fatty acids. Lipoprotein lipases are found in the walls of blood vessels in fat tissue, muscle tissue and heart muscle. Insulin When you eat a candy bar or a meal, the presence of glucose, amino acids or fatty acids in the intestine stimulates the pancreas to secrete a hormone called insulin. Insulin acts on many cells in your body, especially those in the liver, muscle and fat tissue. Insulin tells the cells to do the following: The activity of lipoprotein lipases depends upon the levels of insulin in the body. If insulin is high, then the lipases are highly active; if insulin is low, the lipases are inactive. The fatty acids are then absorbed from the blood into fat cells, muscle cells and liver cells. In these cells, under stimulation by insulin, fatty acids are made into fat molecules and stored as fat droplets. It is also possible for fat cells to take up glucose and amino acids, which have been absorbed into the bloodstream after a meal, and convert those into fat molecules. The conversion of carbohydrates or protein into fat is 10 times less efficient than simply storing fat in a fat cell, but the body can do it. If you have 100 extra calories in fat (about 11 grams) floating in your bloodstream, fat cells can store it using only 2.5 calories of energy. On the other hand, if you have 100 extra calories in glucose (about 25 grams) floating in your bloodstream, it takes 23 calories of energy to convert the glucose into fat and then store it. Given a choice, a fat cell w Continue reading >>
Office Of Science Outreach
Part 3: The Consequences of a High-Fructose Diet When fed fructose, the liver builds fatty acids and assembles them into triglycerides. It exports the triglycerides into the bloodstream, so that they can be taken up by fat cells for storage. The triglyceride-carrier protein is LDL, known as "bad cholesterol." It's a carrier of cholesterol, which attains a lower density by carrying additional triglycerides (which, being less dense than water or protein, make the carrier a "low-density" carrier protein.) Elevated triglycerides and cholesterol are associated with heart disease. Triglycerides are a part of the "metabolic syndrome" disease, which eventually manifests itself as Type 2 Diabetes. The transporter in liver cells, that moves triglycerides from the inside of the cell to the outside, and thus into the bloodstream, can only work so fast. If triglycerides are produced faster than the transporter can export them, the triglycerides build up inside liver cells. They form fat droplets. The liver accumulates fat. Now, in force-fed geese, fatty liver is called foie gras, but fatty liver is not what we want to have. Fatty liver is another of the pre-disposing factors to Type 2 Diabetes. Fructose also leads to alterations in the handling of dietary fat. This has been shown directly in mice. There are significant differences in mice fed identical diets, but with some having their diet supplemented with glucose and others having a supplement of fructose in the same caloric quantity. The glucose-fed mice, when subsequently given fat, metabolize the fat in the production of ATP (as illustrated above). The fructose-fed mice don't do this; they import the fat directly into fat cells for storage. Apparently, fructose not only is converted to fat by the liver, but it changes the way Continue reading >>
Nih Study Shows How Insulin Stimulates Fat Cells To Take In Glucose
Findings could aid in understanding diabetes, related conditions. Using high-resolution microscopy, researchers at the National Institutes of Health have shown how insulin prompts fat cells to take in glucose in a rat model. The findings were reported in the Sept. 8 issue of the journal Cell Metabolism. By studying the surface of healthy, live fat cells in rats, researchers were able to understand the process by which cells take in glucose. Next, they plan to observe the fat cells of people with varying degrees of insulin sensitivity, including insulin resistance — considered a precursor to type 2 diabetes (These observations may help identify the interval when someone becomes at risk for developing diabetes. "What we're doing here is actually trying to understand how glucose transporter proteins called GLUT4 work in normal, insulin-sensitive cells," said Karin G. Stenkula, Ph.D., a researcher at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and a lead author of the paper. "With an understanding of how these transporters in fat cells respond to insulin, we could detect the differences between an insulin-sensitive cell and an insulin-resistant cell, to learn how the response becomes impaired. We hope to identify when a person becomes pre-diabetic, before they go on to develop diabetes." Glucose, a simple sugar, provides energy for cell functions. After food is digested, glucose is released into the bloodstream. In response, the pancreas secretes insulin, which directs the muscle and fat cells to take in glucose. Cells obtain energy from glucose or convert it to fat for long-term storage. Like a key fits into a lock, insulin binds to receptors on the cell's surface, causing GLUT4 molecules to come to the cell's surface. As their name impli Continue reading >>
Curiocity - Curiocit | What Is Glucose For?
Why do you have a sweet tooth? Ever get a sugar high? Why can't my diabetic grandmother have sugar in her coffee? Oddly, the answers to all these questions started at the very beginning of life on earth, before diseases or the ability to taste ever existed. Like a dollar at the shopping mall, glucose (a sugar) is the basic unit of currency for life. Most important is that glucose can be exchanged for energy energy that is used by our bodies to make heat, to move muscles, and to forward all of the chemical reactions needed to keep us alive. Tiny organelles called mitochondria work inside cells to convert glucose into ATP, which is the universal body energy source. Mitochondria, which live inside our cells, have their own DNA and proteins that they make. It is believed that at the beginning of life, mitochondria were separate organisms that were engulfed by larger cells. This marriage was so beneficial to both partners, it has continued in the cells of living things for billions of years! Mitochondria are now the main energy powerhouses of cells and use glucose as their fuel. Glucose is also exchangeable for other important materials in the body. For instance, our bodies convert glucose to fat or glycogen for storage. We can burn that fat by increasing our energy needs, such as by exercise, as the fat gets converted back to glucose (and then energy) to move our muscles. We can even convert protein (amino acids) into glucose, starting with our muscles. This is why athletes and bodybuilders have such large appetites if they don't keep eating their muscles start to dissolve! (Of course, if they keep eating the same and aren't exercising they begin to store glucose as fat in their bellies, like the ex-athlete sportscasters on NFL tv). Why did life use glucose instead of othe Continue reading >>
What Happens To Unburned Carbohydrates?
Your body uses mostly carbohydrates as well as fats for energy. Because the body doesn’t store carbs efficiently, they’re used first. Carbohydrates turn into glucose, which your body burns immediately or converts to glycogen to be stored in the muscles and liver for between meals. If you eat more calories from carbs or other sources than your body can use, the cells store the excess as fat. Of the three major nutrients -- carbohydrates, fat and protein -- the body burns carbs first for energy because they can’t be stored in great quantities. The carbohydrates in food get broken down into glucose, which moves into the small intestine, then the liver and into the blood. As blood sugar rises, the pancreas produces insulin, which signals the cells to take up sugar. Whatever glucose the cells don’t need immediately for energy is stored in the liver and muscles as glycogen. When the blood sugar levels fall -- such as between meals -- the liver releases glycogen. This cycle keeps your body supplied with a steady source of fuel. Insulin Resistance If you have insulin resistance or diabetes, the sugar-insulin cycle doesn’t work properly, leading to too much sugar and insulin circulating in the blood until eventually your body doesn’t produce enough insulin or is resistant to its effects. This is why people with diabetes or prediabetes often track the carbs they eat; eating too many carbohydrates, especially sugars and refined starches, can cause blood sugar and/or insulin to spike to potentially dangerous levels in people with diabetes. How Carbs Turn Into Fat When you eat too many calories, especially in the form of sugars and quickly burned starches, your body may reach its storage capacity for glycogen. The liver converts the stored sugars into triglycerides, or f Continue reading >>