Types of Carbohydrates
Do you shun the breadbasket and pick pasta out of minestrone soup? Do you think carbohydrates are sometimes the enemy? Are you a carb counter? Well, the fact is that we can't live without carbohydrates. Once you know how they work in the body and how to choose the most nutritious ones, you'll see that you can have your carbs, maintain good health, and control your weight, too.Is It Simple or Complex?
How do you know if a food contains simple or complex
carbohydrates? The words simple and complex aren't listed on food
labels. Some foods, like fruits and vegetables, don't have nutrition
labels, and many foods we eat are "combination foods" that provide both
simple and complex carbohydrates. If you're trying to keep your intake
of simple carbohydrates to a minimum, keep this guideline in mind: The
higher the amount of fiber listed, the more complex carbohydrate the
food contains. Many whole grains are complex but not high in fiber,
though, so also check the ingredients list.Many people make the mistake
of thinking that carbohydrate means only bread and pasta-and perhaps cereals and rice. Of course these are carbohydrate foods, but they are by no means the lone sources of carbohydrate. All fruits and vegetables contain carbohydrate, and carbs can also be found in some dairy products. In fact, every plant-based food has carbohydrate in it. Through the process of photosynthesis, plants store carbohydrate as their main energy source.
The foods that contain carbohydrate (grains, beans, fruits, vegetables, and some dairy) are all quite different from each other. But the one thing they have in common, substantial doses of healthy carbohydrate, is something that humans can't live without.
In this article, we will explore everything about the world of carbs -- the different types of carbs, how the body uses carbs, and how carbohydrates are linked to nutrition and obesity. Let's get started by breaking down carbohydrates to their least common denominators.
Breaking Down Carbohydrate
Carbohydrates are made up of a combination of carbon, hydrogen, and oxygen. The word carbohydrate is formed from those words: carbo meaning carbon and hydrate meaning water, which is made of hydrogen and oxygen. Carbohydrates all have these three basic component parts. It's how they are put together that makes each one unique.Carbohydrates are categorized as either simple or complex. The simple carbohydrates are made of a single unit of various arrangements of the three elements (carbon, hydrogen, oxygen). Each unit has the same number of carbon, hydrogen, and oxygen atoms; the different arrangements of them account for their distinct properties, such as sweetness and solubility. Complex carbohydrates are made of different arrangements of these single units that are linked together in various patterns that can be from two to tens of thousands of units long. The more units linked, the more complex the carbohydrate. Simple carbohydrates are sugars; complex carbohydrates are starches, fiber, glycogen, and dextrin.
How to Read Nutrition Labels
The nutrition facts label can help you get a handle on
how much and what type of nutrients you're eating. When searching for
carbohydrate info, do you know what to look for? Here's a primer:
Simple Carbohydrates
the food, such as the lactose in milk and fructose in fruits, as well
as sugar that's been added to the food, such as table sugar, corn
syrup, and dextrose.
There
are two kinds of simple carbohydrates: monosaccharides and
disaccharides. Each type is quite easily broken down by the body to
create the glucose the body uses for energy.
Monosaccharides. These
are the simplest form of carbohydrate ("mono" means one, "saccharide"
means sugar). Glucose, fructose, and galactose, the monosaccharides that
are found in fruits, vegetables, and milk, make up approximately 10
percent of the carbohydrate in our diet. Glucose is often called blood
sugar because it is the main form of carbohydrate that travels through
the bloodstream to provide energy to the body's cells. It's found
naturally in fruits, vegetables, and honey. Fructose, also known as
fruit sugar, is found naturally in many different fruits as well as
honey. Galactose is a monosaccharide that is the end result of the
digestive breakdown of a disaccharide called lactose (the sugar found in
milk).
Disaccharides.
These are made of two single sugar units (monosaccharides) that are
linked together. The different types of disaccharides ("di" means two)
are created through various combinations of monosaccharides. Here are
some examples of disaccharides you might recognize and how they are
formed:
glucose + fructose = sucrose (disaccharide)
glucose + galactose = lactose (disaccharide)
glucose + glucose = maltose (disaccharide)
Sucrose
is the most common disaccharide; it's commonly known as table sugar.
Lactose is the disaccharide found in milk. Maltose is the least common
disaccharide; it's created during digestion by enzymes that break down
large molecules of starch and is a product of cereal grain germination.
Complex Carbohydrates
Complex
carbohydrates are assembled from single sugar units, including glucose,
fructose, and galactose, or pairs of single sugars (the disaccharides,
including sucrose, lactose, and maltose) that are linked together.
Here's how complex carbs are formed:
Polysaccharides. Polysaccharides
("poly" means more than one) are also known as complex carbohydrates
and include starch, fiber, glycogen, and dextrin. Although complex
carbohydrates are built from many single sugar units, they don't taste
sweet. Joining these sugar units together creates the new, complex
carbohydrate-either starch, glycogen, or cellulose (fiber). Starch is
found in plants (starch is their storage form of carbohydrate), glycogen
is the storage form of carbohydrate in humans and animals, and
cellulose, an indigestible form of carbohydrate that's better known as
fiber, provides structure for all plants. A fourth type of
polysaccharide, dextrin, is produced as a result of breaking down long
chains of starch into shorter chains during digestion. All of these
complex carbohydrates are more stable and less soluble than the simple
carbohydrates. However, the body can still break them down fairly easily
into simple sugars and finally into glucose, the simple sugar that the
body uses directly for energy.
The chemical composition of
carbohydrates is a nice starting point, but the real information you
probably want to know about carbs is how they are used by the body. In
the next section, we'll examine what happens when we eat simple and
complex carbohydrates.
How Carbohydrates are Used
Carbohydrate is one of three macronutrients (protein and fat are the other two) that our body requires, and it comprises the bulk of the calories we eat. In fact, 45 to 60 percent of the typical American diet comes from carbohydrate sources. In some parts of the world, particularly in developing countries, carbohydrate consumption may be closer to 80 percent.Plants are rich in carbohydrate, as that is their storage form of energy. When we eat plant-based foods, we ingest this stored energy and put it to use within the body. Although we can use protein and fat to produce energy, carbohydrate is the source of fuel that is easiest for the body to use, and so it is preferred. This is due primarily to the basic chemical structure of carbohydrate -- those units of carbon, hydrogen, and oxygen. Monosaccharides, the simple carbohydrates, are absorbed directly into the bloodstream. But complex carbohydrates are also relatively easy for the body to disassemble, creating glucose that can be shuttled off to cells to provide energy. In fact, the body actually begins to break down carbohydrates in the mouth with the help of an enzyme that is found in saliva.
We need fat in our diets, but also in and on our body -- within limits of course. Dietary fat provides a concentrated source of energy (9 calories per gram). It makes us feel fuller longer, as it tends to leave the stomach slowly, and it transports and supports absorption of the fat-soluble vitamins A, D, E, and K. In the body, fat is the primary form in which humans store excess long-term energy. Fat is not a readily available energy source like carbohydrate; rather, it's meant to sustain us in times of starvation, self-imposed or otherwise. That's one reason why it's so difficult to lose body fat, especially when you cut calories too low. Our body views fat as a source of protection, and it's reluctant to give it up easily. Throughout the body, fat is a component of cell membranes that helps regulate the flow of materials into and out of cells, serves as a precursor to a variety of hormonelike substances that regulate many physiologic processes, acts as an insulator against heat loss, and protects vital organs such as the kidneys and heart.
Protein's power is often underestimated. Sure, protein is made up of amino acids, which the body uses to build new and repair old body tissue and muscle. But protein is a workhorse -- it's part of every body cell and tissue (including organs, skin, bone, and muscle), supports the body's immune functions, aids in the transport of nutrients, serves as a buffer to maintain a stable blood pH, and as enzymes and hormones, works to regulate body processes.
When there isn't enough readily available glucose from the breakdown of carbohydrate, the body first turns to stored carbohydrate reserves (glycogen). If there's still no new intake of carbohydrate and the reserves are depleted, the body is forced to use alternative sources (fat and protein) for energy. When this happens, protein is diverted from its intended job and there isn't much left over to support muscle repair, so muscles can become smaller and weaker.
In extreme cases, such as when a person is on a zero-carb diet, the body can break down muscle to convert into glucose. However, your heart -- the body's main muscle -- is usually protected. The energy needs of the brain and heart are the body's first priority, and it works hard to prevent damage to these and other major organs.
Stoking Our Engines
©2006 .
Complex carbohydrates like fruit cause
your blood sugar to rise slowly and
stay at a constant level.
Our bodies have an amazing ability both to use glucose and to conserve it for future needs. There is a delicate regulatory system that maintains tight control over the level of glucose in the blood.
The regulatory system works like this: When you eat a carbohydrate-containing food or meal, the carbohydrate is absorbed from your digestive tract, causing blood sugar (glucose) levels to rise. Insulin, a hormone released from your pancreas, helps glucose enter your cells, where it is used to produce energy. Your body doesn't turn all of its blood sugar into energy at the same time. Insulin works to both clear glucose from the blood for use by cells and to store any excess in your liver and muscles. This storage form of glucose is called glycogen. Some glucose may also be converted to body fat if you eat more calories than your body needs.
If blood sugar levels drop too low, another hormone called glucagon triggers the conversion of glycogen from the liver back to glucose through a process called glycogenolysis (the breakdown of glycogen). This interplay between insulin and glucagon, in concert with several other physiologic control systems, works to keep blood sugar levels within a normal range at all times. Your body relies on a steady supply of glucose around the clock because your organs never stop working. In fact, a steady supply of glucose is so important that we can produce glucose by an alternate method during periods when we have low glycogen stores or an inadequate intake of carbohydrate. Through a process called gluconeogenesis, protein, and to a lesser extent fat, can be called on to supply glucose to the body, although this is a much more complicated, "fuel expensive," and inefficient process and not the preferred method of obtaining glucose.
Choosing the Best Fuel
If you've ever experienced a headache, grouchy feeling, or lack of concentration because you were too hungry, you can appreciate how important it is to eat every few hours. Skipping meals won't keep your energy level up, but it's important not to grab just anything. Does it really matter what foods you eat? Absolutely! Some foods will raise your blood sugar levels too quickly and drop them like a rock in short order. These foods are the simple carbs, particularly the highly refined foods, such as white bread and candy. Simple carbs are quickly disassembled and absorbed into the bloodstream. While they can temporarily boost your energy, the effect is fleeting because they are used up so quickly. That's why snacking on a candy bar to overcome that mid-afternoon energy slump will likely have the opposite effect. Following a simple carb snack, you may soon experience a significant dip in energy or a return of hunger.Remember the moral of Aesop's story about the tortoise and the hare? Slow and steady wins the race. The hare's burst of energy at the start of the race put him in the lead. But he couldn't maintain the pace and fell behind. The tortoise, on the other hand, plodded along steadily and ended up winning. You can think of simple carbohydrates as the hare and complex carbohydrates as the tortoise. If you supply your body with plenty of complex carbohydrates (whole grains, fruits, vegetables, and legumes) rather than simple carbohydrates, your blood sugar levels will rise more slowly, and they will stay steadier. That means you'll have a more constant supply of energy -- and you'll be a winner every day.
Fiber is an essential part of your diet for many reason. Keep reading to learn more about the important role of fiber in keeping you healthy and how fiber is linked to carbohydrates.
What exactly are whole grains? They are the entire seed grain, or the entire edible portion of any grain, including corn, oats, rice, and others. The whole grain contains three parts: the bran, endosperm, and germ. The bran makes up the outer layers of the grain, the endosperm is the innermost part of the grain, and the germ is the smallest part, otherwise known as the wheat embryo or wheat germ. Together these three parts provide B vitamins, trace minerals, fiber, proteins, phytonutrients, and carbohydrate.
During the milling process, the endosperm is separated from the bran and germ, then ground to the desired consistency, producing white, or refined, flour. For whole-grain flour, the bran and germ are returned to the flour at the end of the process, making it more nutritious. Despite its lack of nutrients, white flour is popular because it produces lighter, airier baked goods.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), ., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.
Carbohydrates in Nutrition and Obesity
Long before processed foods, 24-hour convenience marts, and grocery stores that carry thousands of foods under one roof, humans ate foods in their natural, whole state. Foods that were good sources of fiber and other complex carbohydrates, including fruits, vegetables, nuts, and seeds, were a significant part of the human diet. We ate what nature provided, the way nature provided it.
©2006 .
Eating fewer highly refined processed
foods and more whole grains and whole
fruits and vegetables is better for our
health and for controlling weight.
As revolutionary as this new food processing method was, there was an unfortunate side effect that people weren't aware of immediately. Refinement stripped the grains of most of the nutrients that Mother Nature had built in. But it wasn't just grains that technology was processing. Oranges, a luxury item by themselves, were even more prized in their processed juice form. This unique imported food was advertised in local newspapers, and the upper class bought it, too, as a sign of social status. Unfortunately, some of the nutrients available in whole oranges, particularly fiber, disappeared in processing. Food processing increased the choices available to consumers, but at a nutritional price.
As merchants responded to the need for a year-round food supply by carrying larger inventories, they also needed a way to extend shelf life. Food manufacturers were happy to comply and quickly discovered the profitability of adding preservatives. Fortunately, they also discovered the need to add back nutrients lost in processing, and they developed the ability to do that through enrichment and fortification of their products.
Through the years, many of the ingredients used to extend shelf life, improve palatability, and decrease production costs to manufactured foods have come under fire for their negative impact on the quality of human nutrition. Stripping foods of their natural vitamin, fiber, and mineral package while adding artificial colors, sweeteners, and other additives is not the healthiest or wisest use of technological advancement. Partly out of interest in prevention and partly in response to the steady increase in type 2 diabetes and obesity, as well as the high rate of heart disease and certain cancer diagnoses, the pendulum has slowly begun to swing in the opposite direction. While it's impossible as well as impractical to return to the days when food wasn't refined or preserved in any way, there is increasing recognition that eating fewer highly refined processed foods and more whole grains and whole fruits and vegetables is better for our health and for controlling weight.
Changing diet trends
The link between nutrition, health, and disease grows stronger daily. In the early 1970s, much of the nutrition research linked fat, particularly saturated fat, to heart disease and obesity. But even as the evidence continued to accumulate throughout the 1980s, there seemed to be a disconnect in the message delivery: Americans were growing as well! In fact, according to the Centers for Disease Control, in the last ten years obesity rates have increased by more than 60 percent among adults. Since 1980, obesity rates have doubled among children and tripled among adolescents.
©2006 .
While white flour may have more
commercial appeal, it does not contain
as many nutrients as whole grains.
When fat-free foods didn't appear to be the answer to the skyrocketing obesity rate, people began looking for the next solution. The focus eventually shifted from counting fat grams to counting carbohydrate grams. The theory was the fewer carbohydrates the better. Where fat was concerned, however, all caution was thrown to the wind. As long as people could build a meal around a miniscule amount of carbohydrate, they could eat as much fat and protein as they liked, and the weight was guaranteed to come off. And for some it did come off. But there were unpleasant side effects: Many people who cut carbs significantly felt less energetic and experienced constipation and bloating. And when they ceased to adhere closely to a reduced-carb diet, the weight crept back on. Obesity rates continued to climb. Heart disease remains the number-one killer, and type 2 diabetes is becoming epidemic.
As you can see, it's a mistake to blame carbohydrate alone for obesity and nutrition-related diseases. It is absolutely true, however, to say that the type as well as the amount of carbohydrate that we eat is crucial to good health. We all know that a jelly donut is a carbohydrate food, but it's worlds apart from a whole-wheat bagel in terms of good nutrition. That's what we're talking about here: keeping carbohydrates in the diet but choosing the most nutritious among them.
Originally, the goal of enrichment was simply to replenish the nutrients lost during food processing. Enriched means that nutrients are added back to foods. For instance, white flour is enriched with B vitamins and iron, which are removed from wheat flour when it is refined.
The concept was later expanded to include adding other substances that were not present in the food before processing. The aim of fortifying foods was to eradicate nutritional deficiencies associated with diseases. Fortified means nutrients that are often lacking in typical diets have been added. For example, salt is often fortified with iodine because there are few dietary sources of it.
While vitamins and minerals are still added to processed foods to maintain or improve our current nutritional health, the use of fortification today helps to reduce and prevent devastating and sometimes fatal diseases, such as spina bifida and anencephaly. Fortification of bread, pasta, and other cereal grains with folic acid has been directly responsible for the 26 percent annual decrease in these two birth defects.
Fortification and enrichment may even be new weapons in the fight against heart disease. The amino acid homocysteine is being increasingly accepted as a marker for heart disease risk. High homocysteine and low B vitamin concentrations have been linked to increased risk of cardiovascular disease. Although the role that folic acid and other B vitamins play in heart disease protection still needs to be confirmed, there is encouraging research indicating that fortifying cereals and other foods with folic acid and other B vitamins may help protect against heart disease risk by lowering homocysteine levels.
©.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), ., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.
Carbohydrates in Nutrition and Obesity
Long before processed foods, 24-hour convenience marts, and grocery stores that carry thousands of foods under one roof, humans ate foods in their natural, whole state. Foods that were good sources of fiber and other complex carbohydrates, including fruits, vegetables, nuts, and seeds, were a significant part of the human diet. We ate what nature provided, the way nature provided it.
©2006 .
Eating fewer highly refined processed
foods and more whole grains and whole
fruits and vegetables is better for our
health and for controlling weight.
As revolutionary as this new food processing method was, there was an unfortunate side effect that people weren't aware of immediately. Refinement stripped the grains of most of the nutrients that Mother Nature had built in. But it wasn't just grains that technology was processing. Oranges, a luxury item by themselves, were even more prized in their processed juice form. This unique imported food was advertised in local newspapers, and the upper class bought it, too, as a sign of social status. Unfortunately, some of the nutrients available in whole oranges, particularly fiber, disappeared in processing. Food processing increased the choices available to consumers, but at a nutritional price.
As merchants responded to the need for a year-round food supply by carrying larger inventories, they also needed a way to extend shelf life. Food manufacturers were happy to comply and quickly discovered the profitability of adding preservatives. Fortunately, they also discovered the need to add back nutrients lost in processing, and they developed the ability to do that through enrichment and fortification of their products.
Through the years, many of the ingredients used to extend shelf life, improve palatability, and decrease production costs to manufactured foods have come under fire for their negative impact on the quality of human nutrition. Stripping foods of their natural vitamin, fiber, and mineral package while adding artificial colors, sweeteners, and other additives is not the healthiest or wisest use of technological advancement. Partly out of interest in prevention and partly in response to the steady increase in type 2 diabetes and obesity, as well as the high rate of heart disease and certain cancer diagnoses, the pendulum has slowly begun to swing in the opposite direction. While it's impossible as well as impractical to return to the days when food wasn't refined or preserved in any way, there is increasing recognition that eating fewer highly refined processed foods and more whole grains and whole fruits and vegetables is better for our health and for controlling weight.
Changing diet trends
The link between nutrition, health, and disease grows stronger daily. In the early 1970s, much of the nutrition research linked fat, particularly saturated fat, to heart disease and obesity. But even as the evidence continued to accumulate throughout the 1980s, there seemed to be a disconnect in the message delivery: Americans were growing as well! In fact, according to the Centers for Disease Control, in the last ten years obesity rates have increased by more than 60 percent among adults. Since 1980, obesity rates have doubled among children and tripled among adolescents.
©2006 .
While white flour may have more
commercial appeal, it does not contain
as many nutrients as whole grains.
When fat-free foods didn't appear to be the answer to the skyrocketing obesity rate, people began looking for the next solution. The focus eventually shifted from counting fat grams to counting carbohydrate grams. The theory was the fewer carbohydrates the better. Where fat was concerned, however, all caution was thrown to the wind. As long as people could build a meal around a miniscule amount of carbohydrate, they could eat as much fat and protein as they liked, and the weight was guaranteed to come off. And for some it did come off. But there were unpleasant side effects: Many people who cut carbs significantly felt less energetic and experienced constipation and bloating. And when they ceased to adhere closely to a reduced-carb diet, the weight crept back on. Obesity rates continued to climb. Heart disease remains the number-one killer, and type 2 diabetes is becoming epidemic.
As you can see, it's a mistake to blame carbohydrate alone for obesity and nutrition-related diseases. It is absolutely true, however, to say that the type as well as the amount of carbohydrate that we eat is crucial to good health. We all know that a jelly donut is a carbohydrate food, but it's worlds apart from a whole-wheat bagel in terms of good nutrition. That's what we're talking about here: keeping carbohydrates in the diet but choosing the most nutritious among them.
Originally, the goal of enrichment was simply to replenish the nutrients lost during food processing. Enriched means that nutrients are added back to foods. For instance, white flour is enriched with B vitamins and iron, which are removed from wheat flour when it is refined.
The concept was later expanded to include adding other substances that were not present in the food before processing. The aim of fortifying foods was to eradicate nutritional deficiencies associated with diseases. Fortified means nutrients that are often lacking in typical diets have been added. For example, salt is often fortified with iodine because there are few dietary sources of it.
While vitamins and minerals are still added to processed foods to maintain or improve our current nutritional health, the use of fortification today helps to reduce and prevent devastating and sometimes fatal diseases, such as spina bifida and anencephaly. Fortification of bread, pasta, and other cereal grains with folic acid has been directly responsible for the 26 percent annual decrease in these two birth defects.
Fortification and enrichment may even be new weapons in the fight against heart disease. The amino acid homocysteine is being increasingly accepted as a marker for heart disease risk. High homocysteine and low B vitamin concentrations have been linked to increased risk of cardiovascular disease. Although the role that folic acid and other B vitamins play in heart disease protection still needs to be confirmed, there is encouraging research indicating that fortifying cereals and other foods with folic acid and other B vitamins may help protect against heart disease risk by lowering homocysteine levels.
©.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), ., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.