Carbohydrates are an important part of a general diet because they provide fuel for the body. They are not directly used as building blocks but provide energy for use of fats and proteins and incorporating minerals and vitamins into our bodies. They consist of only Carbon, Oxygen, and Hydrogen atoms -- thus, the name "carbohydrates" although they are not chemically considered to be "hydrates".
When I was double-checking my sources for this article, I found that I had incorrect ideas about alcohol. Alcohol (or, more specifically, ethanol -- drinking alcohol) is NOT considered to be a carbohydrate in spite of having only carbon, oxygen, and hydrogen atoms. However, just as ethanol can be used to fuel machines, our bodies can make use of it as an energy source. Alcohol provides about 7 calories per gram (almost as caloric as fat). Alcohol is not considered to be nutritional and burning alcohol is hard on the body (the liver in particular) and should be used sparingly. A tablespoon of pure alcohol would be about 85 calories -- an 8 ounce glass of wine about 190 calories.
Carbohydrates are largely the same as saccharides. Saccharides are grouped into monosaccharides, disaccharides, oligosaccharides, and polysaccharides. The first two are usually referred to as "sugars" while the other ones have various names including "starches". Since carbohydrates do not provide any "building block" materials the amount can actually be fairly low with calories provided by fats and proteins -- but this is not really recommended. The range of percentage of calories provided by carbohydrates in the diet is suggested to be in the 45% to 65% region.with simple "sugars" limited to around 10%.
It is difficult to discuss carbohydrates without bringing dietary fiber into the discussion. Dietary fiber is looked at as being in two categories -- soluble and insoluble fiber; "good carbs" are talked about versus "bad carbs". It really isn't a matter of the carbohydrates -- it is how they are utilized within the body. The metabolism of carbohydrates (and fats) is regulated by insulin and, thus, eating "simple" carbohydrates will cause a rapid rise of insulin in the body which is hard on the body and related to metabolic problems like diabetes. Soluble fiber works with carbohydrates to allow the digestion to be greatly slowed and extended (look at it as "time released" carbohydrates) and this allows the carbohydrates to be better utilized by the body. A system called the Glycemic Index is a good method of determining the gentleness of different carbohydrates in the diet. Note that insoluble fiber is of use, also, as it provides "roughage" to allow the muscles of the digestive and excremental tracts to be more effective.
One aspect of the Glycemic Index is that it is an isolative, or simplified, look at a single food source. It is possible to still have a gentle diet with simple carbohydrates if it is eaten WITH other foods that can supply the soluble fiber. Thus, rice is not really easy on the body -- but eating rice with high-fiber foods such as beans, or seaweed, or vegetables means that the entire meal is well balanced. This is why many diets that rely on rice are healthy -- it is because they are in combination with other foods which supply needed soluble fiber.
The economics of carbohydrates come into play because simple carbohydrates are inexpensive and, thus, are easily incorporated into unhealthy diets. More balanced carbohydrate sources, such as oats, barley, and beans are also fairly inexpensive but it requires more time to work with them. In the area of applied nutrition, time does equal money. Thus, many fast processed foods have a high percentage of simple carbohydrates and fats. In part six of this series, we will discuss how the choices for food can be made, could be made, and are normally made. (In part five, we will finish up the nutritive discussion with vitamins and minerals.)
In summary, carbohydrates provided needed energy for the body to be active and build cells. In order to be used in a manner that is easier on the body, the entire meal must be planned and examined.
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