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 >>
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 >>
How Is Excess Glucose Stored?
The human body has an efficient and complex system of storing and preserving energy. Glucose is a type of sugar that the body uses for energy. Glucose is the product of breaking down carbohydrates into their simplest form. Carbohydrates should make up approximately 45 to 65 percent of your daily caloric intake, according to MayoClinic.com. Video of the Day Glucose is a simple sugar found in carbohydrates. When more complex carbohydrates such as polysaccharides and disaccharides are broken down in the stomach, they break down into the monosaccharide glucose. Carbohydrates serve as the primary energy source for working muscles, help brain and nervous system functioning and help the body use fat more efficiently. Function of Glucose Once carbohydrates are absorbed from food, they are carried to the liver for processing. In the liver, fructose and galactose, the other forms of sugar, are converted into glucose. Some glucose gets sent to the bloodstream while the rest is stored for later energy use. Once glucose is inside the liver, glucose is phosphorylated into glucose-6-phosphate, or G6P. G6P is further metabolized into triglycerides, fatty acids, glycogen or energy. Glycogen is the form in which the body stores glucose. The liver can only store about 100 g of glucose in the form of glycogen. The muscles also store glycogen. Muscles can store approximately 500 g of glycogen. Because of the limited storage areas, any carbohydrates that are consumed beyond the storage capacity are converted to and stored as fat. There is practically no limit on how many calories the body can store as fat. The glucose stored in the liver serves as a buffer for blood glucose levels. Therefore, if the blood glucose levels start to get low because you have not consumed food for a period of time Continue reading >>
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- Exercise and Blood Glucose Levels
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 >>
Glucose Storage In People
Now, all you wiseacres out there probably said on the shelf, or in a jar - and I guess that could answer the question! But how does your BODY (or Monomer Mouse's little body) store glucose so that it can get to it fast and easy for quick energy? We make a polymer called glycogen, which is a lot like starch. It's made out of repeating glucose units put together just like starch, and it has a lot of branches - (more than starch does). Like starch, glycogen curls around and forms a big globby structure. Because it's branched and globby, glycogen has ends sticking out all over. Enzymes can attach onto those ends and break the glycogen down fast into glucose units, that can be broken down further (by a bunch of other enzymes) to make ENERGY! So, where would you expect glycogen to be? Where you need it the most - in your muscles so you can run fast with a burst of energy. (Glycogen is also in your liver.) Glycogen is really short-term storage. For long-term storage of energy, your body turns that glucose into fat. Fat is a pretty big molecule, but it's not a polymer. Fat can be stored compactly in special cells (called adipose) because it doesn't dissolve in water - it forms droplets in special compartments in adipose cells. So there you go! That's how your body stores energy. When you eat starch, your body breaks it down into glucose, then makes glycogen for short-term storage. If there's a bunch left over that's not needed, fat is made for long-term storage. Content by Patricia DePra; Graphics by Virginia Smith. Continue reading >>
Eleven Myths And Facts About How The Body Burns Fat
The reality is that working out in the fat burning zone doesn’t measure up as the ideal exercise mode for losing body fat. Most important for fat loss is that the energy (calories) that is entering the body is less than the energy leaving the body. There are lots of ways of making this happen. This article will give you 11 fat loss facts, covering everything from how the body burns energy to when and how to focus on enhanced fat burning so as to optimize body composition. #1. Knowing where and how energy is stored in the body will improve fat loss results. Your body has the following energy sources available to it, which it burns at different rates depending on the intensity of physical activity: • Body fat provides roughly 30,000-100,000 calories in normal-weight people, depending on how much body fat you actually have. In obese people, the number is much higher. • Muscle glycogen provides 1,400-2,000 calories or 350-500 grams of glycogen, which is enough for 90 minutes of endurance exercise. It is stored in muscle cells and used by those cells for energy. • Liver glycogen provides about 400 calories or 100 grams of glycogen. It can be turned into glucose and used by the rest of the body, such as the brain and blood cells. • There’s also muscle and tissue, which is made of amino acids and can be broken down to produce glucose. This is the not ideal because it leads to loss of lean mass. #2. During exercise, the intensity of the exercise dictates the proportion of fat or carbohydrates being burned. Fat is your body’s primary fuel when you haven’t just eaten and aren’t exercising (a state we call “at rest”). At rest, when you’re sitting at your desk or even going for a walk, your body is burning mostly fat, but depending on the need for energy (su Continue reading >>
Converting Carbohydrates To Triglycerides
Consumers are inundated with diet solutions on a daily basis. High protein, low fat, non-impact carbohydrates, and other marketing “adjectives” are abundant within food manufacturing advertising. Of all the food descriptors, the most common ones individuals look for are “fat free” or “low fat”. Food and snack companies have found the low fat food market to be financially lucrative. The tie between fat intake, weight gain, and health risks has been well documented. The dietary guidelines suggest to keep fat intake to no more than 30% of the total diet and to consume foods low in saturated and trans fatty acids. But, this does not mean that we can consume as much fat free food as we want: “Fat free does not mean calorie free.” In many cases the foods that are low in fat have a large amount of carbohydrates. Carbohydrate intake, like any nutrient, can lead to adverse affects when over consumed. Carbohydrates are a necessary macronutrient, vital for maintenance of the nervous system and energy for physical activity. However, if consumed in amounts greater than 55% to 65% of total caloric intake as recommended by the American Heart Association can cause an increase in health risks. According to the World Health Organization the Upper Limit for carbohydrates for average people is 60% of the total dietary intake. Carbohydrates are formed in plants where carbons are bonded with oxygen and hydrogen to form chains of varying complexity. The complexity of the chains ultimately determines the carbohydrate classification and how they will digest and be absorbed in the body. Mono-and disaccharides are classified as simple carbohydrates, whereas polysaccharides (starch and fiber) are classified as complex. All carbohydrates are broken down into monosaccharides before b 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 Are Carbohydrates Converted Into Fat Deposits?
How are carbohydrates converted into fat deposits? There are two ways that carbohydrates and body fat interact. One is directly by turning into body fat, and the other is via insulin. Turning into body fat is like adding fat into the fat cells, whereas carbohydrates spiking insulin does not add anything to fat cells per se, but hinders the release. The former is like a + equation, where the latter is a double negative which results in something that seems positive. There is a process called de novo lipogenesis (literally: Creation of fat from non-fat sources) that can occur in the body. This process turns glucose into lipids, which are then stored as body fat. This process is normally quite inefficient in the body  , which suggests that carbohydrates cannot be stored as fat to a high degree. The process can be upregulated (enhanced) if dietary fat comprised almost none of the diet (lesser than 10%, as a rough estimate), if carbohydrate intake is excessively high for a period of a few days, or if one follows an obesogenic diet (diet that is likely to make you fat) for a prolonged period of time.    Carbohydrates spike insulin , which is a hormone that mediates glucose metabolism. Insulin is not good or bad, insulin is insulin. It can be thought of as a lever that switches the body from fat burning mode into carbohydrate burning mode. This allows carbohydrates (and glycogen) to be burnt at a greater rate, but directly reduces the ability of fat to be lost. Overall metabolic rate (calories burnt over the course of a day) does not change significantly, just where the calories come from. When insulin is spiked in presence of ingested dietary fat, the dietary fat can go into body fat stores and not be released since glucose from glycogen is being used in place of Continue reading >>
How Is Glucose Stored In The Liver?
The liver is large and in charge. The dark reddish-brown organ sits in the upper right abdomen and, at about 3 pounds, is the largest one inside the body (the skin is the largest organ overall). The liver manages a dizzying array of tasks, including digesting fats, making and storing glucose, and serving as the body's detox center. Glucose Warehouse The liver is an insulin-guided organ: Its behavior changes depending on the level of the hormone insulin in the body and how sensitive the liver is to that insulin. After eating, blood glucose levels rise, which in people without diabetes triggers the pancreas to release insulin into the blood. Insulin is the signal for the body to absorb glucose from the blood. Most cells just use the glucose to supply them with energy. But the liver has a special job when it comes to glucose. When levels of glucose (and consequently insulin) are high in the blood, the liver responds to the insulin by absorbing glucose. It packages the sugar into bundles called glycogen. These glucose granules fill up liver cells, so the liver is like a warehouse for excess glucose. When glucose levels drop, insulin production falls, too. The shortage of insulin in the blood is the signal that the liver needs to liquidate its assets, sending its glucose stores back into the blood to keep the body well fed between meals and overnight. The liver doles out stored glucose and has the singular ability to make glucose from scratch. This is a critical function that keeps people alive when food is scarce. In people with diabetes, however, the liver doesn't process and produce glucose normally, adding to the challenge of blood glucose control. The liver can't directly detect blood glucose levels; it knows only what insulin tells it. So, if there is a shortage of ins Continue reading >>
Why We Get Fat
Here's an big picture view of why we get fat and how high intensity exercise and a ketogenic, low carb diet can help with fat loss. (click picture for larger image as you read explanation below..) When you eat food and especially carbohydrates, your body uses a hormone called insulin to store the glucose (sugar) that is made from the foods you eat. If you eat lots of carbohydrates, lots of insulin is released to quickly remove the sugar from the bloodstream into your cells where it can be stored. This is a critical function because large amounts of circulating glucose can damage your body via a process called glycosylation. Imagine what maple syrup would do if it was poured on your computer's inner circuits. All the working parts would get super sticky and stop functioning correctly. Insulin's job is to move that sugar out of your bloodstream and into storage as a molecule called glycogen. However, the human capacity to store carbohydrate as glycogen is limited. In a 154 pound man, only about 1800 calories can be stored as glycogen. Some is stored in the liver to be used by the brain, and some is stored in our skeletal muscles as glycogen fuel reserves. The muscle based glycogen is meant to be a sort of "turbo charge" in a "fight or flight" situation, and for any other quick and hard work done by muscle. However, if you don't use this "turbo" fuel by exercising, it stays in the muscles. Once the storage limits are reached in the liver and muscle, your glycogen "tank" is full and no more glycogen can be stored there. When the glycogen tanks are full, the cells of your liver and muscles put up a "stop sign" to insulin. They do this by "downgrading" or desensitizing the insulin receptors on their cellular surface. Since the insulin signal is being ignored, unstored glucose 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 >>
- NZ case study; A citizen scientist controls autoimmune diabetes without insulin, with a low carb diet, a glucose meter, and metformin.
- Insulin, glucagon and somatostatin stores in the pancreas of subjects with type-2 diabetes and their lean and obese non-diabetic controls
- British doctors trial simple gut operation that 'cures or controls' diabetes
Schematic two-dimensional cross-sectional view of glycogen: A core protein of glycogenin is surrounded by branches of glucose units. The entire globular granule may contain around 30,000 glucose units. A view of the atomic structure of a single branched strand of glucose units in a glycogen molecule. Glycogen (black granules) in spermatozoa of a flatworm; transmission electron microscopy, scale: 0.3 µm Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in humans, animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Glycogen functions as one of two forms of long-term energy reserves, with the other form being triglyceride stores in adipose tissue (i.e., body fat). In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle. In the liver, glycogen can make up from 5–6% of the organ's fresh weight and the liver of an adult weighing 70 kg can store roughly 100–120 grams of glycogen. In skeletal muscle, Glycogen is found in a low concentration (1–2% of the muscle mass) and the skeletal muscle of an adult weighing 70 kg can store roughly 400 grams of glycogen. The amount of glycogen stored in the body—particularly within the muscles and liver—mostly depends on physical training, basal metabolic rate, and eating habits. Small amounts of glycogen are also found in other tissues and cells, including the kidneys, red blood cells, white blood cells,[medical citation needed] and glial cells in the brain. The uterus also stores glycogen during pregnancy to nourish the embryo. Approximately 4 grams of glucose are present in the blood of humans at all times; in fasted individuals, blood glucos 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 >>
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 >>