Carbohydrate Basics

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.

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.

Contents

1. Breaking Down Carbohydrate
2. How Carbohydrates are Used
3. Choosing the Best Fuel
4. Carbohydrates in Nutrition and Obesity
5. Carbohydrates in Nutrition and Obesity

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.

Simple Carbohydrates

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.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., 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.

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.

Eating an abundance of carbohydrate is essential because it provides a steady and readily available supply of energy to the body. In fact, it is the main source of energy for the brain and the central nervous system. A constant supply of glucose is necessary for the brain and nerve tissues to function properly. If you don’t eat enough carbohydrate, the body will turn to other sources, such as fat, to meet its energy needs. While our body has the ability to use alternative sources (including protein) for fuel, it’s ill-advised to reduce carbohydrate intake enough to force the body into this state. That’s why the strategy behind some low-carbohydrate diets — to encourage the body to burn fat for fuel — may sound like a good idea but in actuality is not.

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 Publications International, Ltd. Complex carbohydrates like fruit cause your blood sugar to rise slowly and stay at a constant level.

Even if we eat sufficient amounts of carbohydrate every day to fuel our energy needs, we don’t eat continuously. Yet our bodies need glucose all the time, not just at mealtimes or when we feel like having a snack. So how does the body manage to keep providing a constant supply of glucose to the cells?

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.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., 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 Publications International, Ltd. Eating fewer highly refined processed foods and more whole grains and whole fruits and vegetables is better for our health and for controlling weight.

That began to change with the advent of new technologies that allowed us to process foods in a way we never had before. Not only did we learn to mill whole grains in volume to feed an ever-growing population, but we also learned how to refine them even further into white flour. While pricey, the white flour gave breads and other baked goods more visual and textural appeal. This was not lost on the upper class, who flaunted their higher social status by serving foods prepared with refined, white flour.

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 Publications International, Ltd. While white flour may have more commercial appeal, it does not contain as many nutrients as whole grains.

During the mid- to late-1980s, food scientists and manufacturers began working to become part of the solution to the growing obesity problem by developing fat-free and low-fat foods. Since fat has more than double the calories found in protein and carbohydrate, it seemed reasonable to assume that cutting fat in foods was a good way to cut calorie consumption overall. Consumers eagerly jumped on the bandwagon, buying lots of fat-free products. However, much to everyone's surprise, obesity rates continued to climb at an alarming rate. Why? The fat-free products contained considerably more refined carbohydrate (sugar) to substitute for the loss of flavor from fat. The products may have been fat free, but they weren't calorie free. But people acted as if they were, consuming huge quantities of processed fat-free cookies, crackers, and other goodies.

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.

^©Publications International, Ltd.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., 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 Publications International, Ltd. Eating fewer highly refined processed foods and more whole grains and whole fruits and vegetables is better for our health and for controlling weight.

That began to change with the advent of new technologies that allowed us to process foods in a way we never had before. Not only did we learn to mill whole grains in volume to feed an ever-growing population, but we also learned how to refine them even further into white flour. While pricey, the white flour gave breads and other baked goods more visual and textural appeal. This was not lost on the upper class, who flaunted their higher social status by serving foods prepared with refined, white flour.

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 Publications International, Ltd. While white flour may have more commercial appeal, it does not contain as many nutrients as whole grains.

During the mid- to late-1980s, food scientists and manufacturers began working to become part of the solution to the growing obesity problem by developing fat-free and low-fat foods. Since fat has more than double the calories found in protein and carbohydrate, it seemed reasonable to assume that cutting fat in foods was a good way to cut calorie consumption overall. Consumers eagerly jumped on the bandwagon, buying lots of fat-free products. However, much to everyone's surprise, obesity rates continued to climb at an alarming rate. Why? The fat-free products contained considerably more refined carbohydrate (sugar) to substitute for the loss of flavor from fat. The products may have been fat free, but they weren't calorie free. But people acted as if they were, consuming huge quantities of processed fat-free cookies, crackers, and other goodies.

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.

^©Publications International, Ltd.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., 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.