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How Is Excess Glucose Converted To Fat For Storage?

Utilization Of Dietary Glucose In The Metabolic Syndrome

Utilization Of Dietary Glucose In The Metabolic Syndrome

Utilization of dietary glucose in the metabolic syndrome 1Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Barcelona, Spain 2CIBER Obesity and Nutrition, Institute of Health Carlos III, Spain 1Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Barcelona, Spain 2CIBER Obesity and Nutrition, Institute of Health Carlos III, Spain Received 2011 Sep 20; Accepted 2011 Oct 26. Copyright 2011 Alemany; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC. This review is focused on the fate of dietary glucose under conditions of chronically high energy (largely fat) intake, evolving into the metabolic syndrome. We are adapted to carbohydrate-rich diets similar to those of our ancestors. Glucose is the main energy staple, but fats are our main energy reserves. Starvation drastically reduces glucose availability, forcing the body to shift to fatty acids as main energy substrate, sparing glucose and amino acids. We are not prepared for excess dietary energy, our main defenses being decreased food intake and increased energy expenditure, largely enhanced metabolic activity and thermogenesis. High lipid availability is a powerful factor decreasing glucose and amino acid oxidation. Present-day diets are often hyperenergetic, high on lipids, with abundant protein and limited amounts of starchy carbohydrates. Dietary lipids favor their metabolic processing, saving glucose, which additionally spares amino acids. The glucose excess elicits hyperinsulinemia, wh Continue reading >>

Does Carbohydrate Become Body Fat?

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 >>

When Does Glucose Convert To Fat?

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 >>

Converting Carbohydrates To Triglycerides

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 Is Excess Glucose Stored?

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 >>

Glucose

Glucose

Physiology • Glucose in the blood is derived from three main sources: ○ ▪ Glucose is the end-product of carbohydrate digestion, absorbed by enterocytes. ▪ Increased blood glucose concentrations occur 2 to 4 hours after a meal in simple-stomached animals. ○ Hepatic production ▪ Gluconeogenesis and glycogenolysis within hepatic cells produce glucose when metabolically necessary. □ Gluconeogenesis converts noncarbohydrate sources, primarily amino acids (from protein) and glycerol (from fat), in simple-stomached animals. □ Glycogenolysis converts glycogen (poly-glucose) stored in hepatocytes to glucose through hydrolysis. ▪ Gluconeogenesis and glycogenolysis within hepatic cells produce glucose when metabolically necessary. □ Gluconeogenesis converts noncarbohydrate sources, primarily amino acids (from protein) and glycerol (from fat), in simple-stomached animals. □ Glycogenolysis converts glycogen (poly-glucose) stored in hepatocytes to glucose through hydrolysis. ○ ▪ Gluconeogenesis and glycogenolysis within renal epithelial cells can result in the formation of glucose when metabolically necessary. • The plasma concentration of glucose is controlled by a number of hormones, in particular, insulin and glucagon. The physiology of glucose homeostasis is controlled primarily by insulin release in response to elevated glucose levels (postprandial), although in birds, glucagon appears to serve as the primary regulator. Significant species variations in glucose levels have been noted. In general, levels are lowest in reptiles (60 to 100 mg/dL) and highest in birds (200 to 500 mg/dL), with mammals in between (100 to 200 mg/dL). Glucose that is not needed for energy is stored in the form of glycogen as a source of potential energy, readily available whe Continue reading >>

A&p 2 Ch. 25a Flashcards | Quizlet

A&p 2 Ch. 25a Flashcards | Quizlet

contains twice as much energy as carbs, they are harder to catabolize. is a form of lipid catabolism. catabolized into glycerol and fatty acids by bile and lipases. This is promoted by cortisol, epinephrine and norepinephrine. is converted to glyceraldehyde 3 phosphate, part of the glycolysis pathway. If individual DOES NOT need ATP, G 3-P converted into glucose to be stored for later! if individual DOES need ATP, G 3-P will undergo glycolysis, producing pyruvic acid which will continue through the steps of cellular respiration. is called beta oxidation (occurs in inner matrix of mitochondria) fatty acid chain broken down into small fragments consisting on two carbon atoms. The two carbon fragments are attached to coenzymes A to form acetyl coenzyme A which can enter the krebs cycle and continue through cell respiration. hepatocytes can take two acetyl Co A molecules and condense them into X acid this will occur if there are many acetyl CoA molecules in blood. Some acetoacetic acid is converted into B-hydroxybutyric acid and acetone (all three substances called ketone bodies) Detone bodies diffuse into the blood and can be used by other cells to make acetyl CoA again. excessive production of ketone bodies. Ketone bodies are acidic and must be buffered, but if there are too many then the buffer systems can't keep up. accumulation of too many ketone bodies cause an abnormally low blood pH-> causes depression of the CNS which can lead to a coma or death. is a type of anabolism which occurs when more calories are ingested than are needed to make ATP. X is the most common lipid in our diet and are stored as they are. This is also called lipogenesis and is a type of anabolism. are converted to triglycerides and then stored. This is also called lipogenesis and is a type of an Continue reading >>

How Do Carbohydrates Turn Into Fats?

How Do Carbohydrates Turn Into Fats?

Originally Answered: Do carbs turn into fat? Any carbs which are not used immediately or stored (as others have described well) in small quantities in the muscles and liver, are converted into body fat. So are excess fat and protein that don't get used relatively quickly. The problem with carbs is that they raise insulin levels. The body needs insulin to get sugar (from carbs) out of the bloodstream and into body cells where it can be burned for fuel. But for some people--many people, especially those who eat lots and lots of sugar--their body becomes insulin-resistant, and the cells refuse to let the blood sugar in. So the body makes even more insulin, trying to get the sugar into the cells, and this cycle keeps building. (Eventually the pancreas wears out from producing so much insulin, and the person develops Type 2 diabetes...which then gets treated with increasing amounts of injected insulin....) Insulin also tells your body to store fat. So when your insulin levels are always high--because you have become insulin resistant, or because you eat carbs all day long without stopping--you are always storing your extra calories, instead of burning them. Your body literally cannot burn fat while insulin levels are high. People who eat traditional diets, with little sugar, can often eat carbs without getting fat. They don't become insulin resistant. The sugar gets into the cells and burned as fuel, the insulin levels drop, and then the body burns excess fat, as it was built to do. Something about eating huge amounts of sugar seems to cause insulin resistance (and thus obesity and diabetes). They don't know exactly why, but the research is fairly clear. And sugar has not been a big part of the human diet for most of human existence. So the answer is...not always. But for t Continue reading >>

How Are Carbohydrates Converted Into Fat Deposits?

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 [1] , 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. [1] [2] [3] 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 >>

What Happens To Unburned Carbohydrates?

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 >>

How Sugar Makes You Fat

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 >>

Carbohydrate Metabolism

Carbohydrate Metabolism

Carbohydrate metabolism denotes the various biochemical processes responsible for the formation, breakdown, and interconversion of carbohydrates in living organisms. Carbohydrates are central to many essential metabolic pathways.[1] Plants synthesize carbohydrates from carbon dioxide and water through photosynthesis, allowing them to store energy absorbed from sunlight internally.[2] When animals and fungi consume plants, they use cellular respiration to break down these stored carbohydrates to make energy available to cells.[2] Both animals and plants temporarily store the released energy in the form of high energy molecules, such as ATP, for use in various cellular processes.[3] Although humans consume a variety of carbohydrates, digestion breaks down complex carbohydrates into a few simple monomers for metabolism: glucose, fructose, and galactose.[4] Glucose constitutes about 80% of the products, and is the primary structure that is distributed to cells in the tissues, where it is broken down or stored as glycogen.[3][4] In aerobic respiration, the main form of cellular respiration used by humans, glucose and oxygen are metabolized to release energy, with carbon dioxide and water as byproducts.[2] Most of the fructose and galactose travel to the liver, where they can be converted to glucose.[4] Some simple carbohydrates have their own enzymatic oxidation pathways, as do only a few of the more complex carbohydrates. The disaccharide lactose, for instance, requires the enzyme lactase to be broken into its monosaccharide components, glucose and galactose.[5] Metabolic pathways[edit] Overview of connections between metabolic processes. Glycolysis[edit] Glycolysis is the process of breaking down a glucose molecule into two pyruvate molecules, while storing energy released Continue reading >>

Why Eating Too Many Carbs Makes You Fat

Why Eating Too Many Carbs Makes You Fat

Carbs and carbs alone, not fat, increase body weight. It doesn't matter whether the carbs are from sugar, bread, fruit, or vegetables: They’re all rapidly digested and quickly converted to blood glucose. A short time after a carb-rich meal, the glucose in your bloodstream rises rapidly, and your pancreas produces a large amount of insulin to take the excess glucose out. Just as eating fat doesn’t raise blood glucose, it doesn't raise insulin levels either. This is important because insulin is the hormone responsible for body fat storage. Because fats do not elicit an insulin response, they cannot be stored as body fat. Insulin takes glucose out of the bloodstream. It is converted first into a starch called glycogen, which is stored in the liver and in muscles. But the body can store only a limited amount of glycogen, so the excess glucose is stored as body fat. This is the process of putting on weight. When your blood glucose level returns to normal, after about 90 minutes, the insulin level in your bloodstream is still near maximum. As a result, the insulin continues to stack glucose away in the form of fat. Ultimately, the level of glucose in your blood falls below normal, and you feel hungry again. So you have a snack of more carbohydrates, and the whole process starts over again. You're getting fatter, but feeling hungry at the same time. Ultimately, insulin resistance caused by continually high insulin levels in your bloodstream impairs your ability to switch on a satiety center in the brain. You enter a vicious cycle of continuous weight gain combined with hunger. Under such circumstances, it is almost impossible not to overeat. Taking Off Weight: Only Cutting Carbs Can Do It So you've put the weight on–now you need to take it off again. Here again, “healt Continue reading >>

How Fat Cells Work

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 >>

Why We Get Fat

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 >>

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