You can see that glucose is made of 6 carbon atoms (carbo...) and the elements of 6 water molecules (...hydrate).

Glucose is a simple sugar, meaning that to our tongues it tastes sweet. There are other simple sugars that you have probably heard of. Fructose is the main sugar in fruits. Fructose has the same chemical formula as glucose (C₆H₁₂O₆), but the atoms are arranged slightly differently.

The liver converts fructose to glucose. Sucrose, also known as "white sugar" or "table sugar," is made of one glucose and one fructose molecule bonded together.

Lactose (the sugar found in milk) is made of one glucose and one galactose molecule bonded together. Galactose, like fructose, has the same chemical components as glucose but the atoms are arranged differently.

The liver also converts galactose to glucose. Maltose, the sugar found in malt, is made from 2 glucose atoms bonded together.

Glucose, fructose and galactose are monosaccharides and are the only carbohydrates that can be absorbed into the bloodstream through the intestinal lining. Lactose, sucrose and maltose are disaccharides (they contain 2 monosaccharides) and are easily converted to their monosaccharide bases by enzymes in the digestive tract.

Monosaccharides and disaccharides are called simple carbohydrates. They are also sugars, they all taste sweet. They all digest quickly and enter the bloodstream quickly. When you look at a "Nutrition Facts" label on a food package and see "Sugars" under the "Carbohydrates" section of the label, these simple sugars are what the label is talking about.

There are also complex carbohydrates, commonly known as "starches." A complex carbohydrate is made up of chains of glucose molecules. Starches are the way plants store energy, plants produce glucose and chain the glucose molecules together to form starch.

Most grains (wheat, corn, oats, rice) and things like potatoes and plantains are high in starch. Your digestive system breaks a complex carbohydrate (starch) back down into its component glucose molecules so that the glucose can enter your bloodstream.

It takes a lot longer to break down a starch, however. If you drink a can of soda full of sugar, glucose will enter the bloodstream at a rate of something like 30 calories per minute. A complex carbohydrate is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute (reference).

You may have heard that eating complex carbohydrates is a good thing and that eating sugar is a bad thing. You may even have felt this in your own body. The following quote from The Yale Guide to Children's Nutrition explains why:

If complex carbohydrates are broken down to monosaccharides in the intestines before they are absorbed into the bloodstream, why are they better than refined sugar or other di- or mono-saccharides?

To a great extent it has to do w/the processes of digestion and absorption. Simple sugars require little digestion and when a child eats a sweet food, such as a candy bar or a can of soda, the glucose level of the blood rises rapidly.

In response, the pancreas secretes a large amount of insulin to keep blood glucose levels from rising too high. This large insulin response in turn tends to make the blood sugar fall to levels that are too low 3 to 5 hours after the candy bar or can of soda has been consumed.

This tendency of blood glucose levels to fall may then lead to an adrenaline surge, which in turn can cause nervousness and irritability...

The same roller-coaster ride of glucose and hormone levels is not experienced after eating complex carbohydrates or after eating a balanced meal because the digestion and absorption processes are much slower.

If you think about it, this is incredibly interesting because it shows that the foods you eat and the way you eat them can affect your mood and your temperament. Foods do that by affecting the levels of different hormones in your bloodstream over time.

Another interesting thing about this quote is its mention of insulin. It turns out that insulin is incredibly important to the way the body uses the glucose that foods provide. The functions of insulin are:

• To enable glucose to be transported across cell membranes
• To convert glucose into glycogen for storage in the liver and muscles
• To help excess glucose be converted into fat
• To prevent protein breakdown for energy

The Untold Truth About Carbohydrates - By Allan Boshell

Do you want the truth? Just how bad are carbohydrates?

After all every food advertisement you see today makes it sound like you should hunt down and destroy the pesky things. I mean every food is now given a net carb count.

Even beer commercials are going low carb. Geez, beer never had more than 4 or 5 grams to begin with and the calories in beer haven’t changed. Nah, it’s just that now you read the label more closely and realize there are actually carbs in beer. Before Atkins and South Beach all we cared about was how much alcohol was in beer!

So, are carbohydrates really the bad guys they’re being made out to be?

I mean people are losing weight like crazy on the South Beach diet so there must be some truth to the fact that carbs are bad?

Well - drum roll please - there is a whole lot of truth to all this fuss about carbs. In fact, most of the carbohydrates in the typical American diet should be eliminated.

But let's not throw the baby out with the bath water. Some are bad and others aren’t so bad but the life and death truth is this…

…You must have carbohydrates to sustain a healthy body and a sharp mind.

There is simply no way around this physiological fact. You see carbs are the fuel that keeps your motor running. They're like gasoline to an engine.

The real key is to understand which ones are best for the engine.

Let me introduce you to Complimentary Carbs. What are Complimentary Carbs?

Complimentary carbs will do two very important things for you:

They'll assist you in weight loss and,
They'll support an active, fitness oriented lifestyle.

Look at it this way: You and a friend are traveling to the same destination and you're traveling in identical cars. You both have only five gallons of gas. However, your friend is taking the highway and you're taking the city streets to the destination.

Your trip is stop and go, heavy acceleration then slow down for a red light. Get up to 55 mph then down again to a crawl. Stop-go, stop-go. Accelerate fast-slow down.

Your friend gets on the highway, sets the car on cruise control and leisurely steers the car until time to exit and pull into the parking lot. Your friends’ car has 2 gallons of gas left over when she arrives.

You're on empty and barely get to your destination. What was the difference?

The difference is this:

You gave your car more fuel than it could use with all the heavy acceleration, slow down, speed up, stop-go driving. That unused fuel went through your catalytic converter and into the street and atmosphere.

Your body is similar. Give it more fuel all at one time than it can use and your catalytic converter (insulin) will send it away as fat.

Carbohydrates that give you a big rush of sugar (white bread, rice cakes, watermelon) are for your body like the city streets are for your car.

Complimentary carbs are more like the cruise control – easy, smooth and gradual. Giving you all the fuel you need without wasting a bit (storing it as fat).

You see, because complimentary carbs release their energy slower, (this means they have a lower glycemic index) your body can maintain a more stable blood sugar level. This is good because you will have sustained energy over a longer period and your body will have access to smaller, even “doses” of energy.

These smaller doses give you the time to actually utilize the sugar (glucose = fuel) thereby preventing an “overdose” and the need to store any excess as fat.

Diabetics typically eat these foods to help them regulate spikes in their blood sugar and to help them to be less dependent on insulin. In other words, diabetics can often manage their disease simply by regulating the kind of carbohydrates they eat.

Better yet, there’s an added bonus…

…when you eat these “complimentary” foods many of them have considerable fiber content and they require more calories to digest. As a result, these complimentary carbs not only give you more sustained energy over a longer period they also help you to develop a better daily ‘burn” rate (as in calories) and ultimately aid in weight loss.

Thus, I call them complimentary foods. They compliment your efforts at maintaining energy balance and ideal weight. Eating them is what I call complimentary eating.

Space doesn’t allow for a long list of these foods. However, there is a terrific web site at www.mendosa.com/gi.htm that provides a great deal of information on the glycemic index of foods and provides an extensive list of foods and their glycemic index. When looking at this list of foods, note that the complimentary carbs are those with the lower glycemic index.

So what do you do with this information in real life?

1. Increase your consumption of foods that are low on the glycemic index and avoid those that are high on the list.

2. Cut back on refined flower and processed foods by avoiding the aisles of the super market.

3. Avoid eating too many “diet” foods. What does that mean anyway?

4. Just eat fresher more colorful foods and more old-fashioned foods (slow cook oatmeal, lentils, barley, nuts) and lots and lots of green stuff.

5. Take care not to fall prey to food manufacturer “spin”. All the labels for net carb, useable carb, low carb and no carb are mostly lies and marketing hype. There are still more calories in a gram of alcohol than in a gram of carbohydrate so low carb beer just doesn’t matter. Low alcohol beer is better but who wants to drink that?

6. Eat more often from your own kitchen. I know, I know I don’t have time either. But face it, life is the stuff that always gets in the way of your plans but you plan anyway don’t you? So maybe you can cook a bunch of complimentary foods and have leftovers if time is a premium.

7. If eating at home isn't possible try to get as educated as possible on good carbs and protein and eat prepared meals containing smart choices.

Eating well need not be an exercise in deprivation nor biochemistry. Eating carbs need not be the end of good eating. Once you make a few small adjustments and see results it gets easier to make a few more and to be a good judge of choices.

Before long these small steps have made a considerable distance and your results will show. You’ll maintain or lose weight at will and still enjoy the goodness of carbs.