Understanding carbohydrates - Essay Example

Carbohydrates are a major source of energy needed for accomplishing everyday physical activities and bodily functions. According to the Canadian Sugar Institute (1997), carbohydrates make up for 40 to 80 percent of the total food energy intake among humans worldwide. As the name implies, carbohydrates are carbon hydrates, that is, they are formed from the union of carbon, hydrogen and oxygen. They are commonly taken from cereals, root crops, sugar crops, pulses, vegetables, fruit and milk products (Canadian Sugar Institute, 1997).

Some sources of carbohydrates have undergone processing and therefore have different effects on the body as compared to those carbohydrates that did not go through refinements or processes. Because of this, it becomes essential to properly select the carbohydrate-rich foods that would be included in the everyday diet.Carbohydrates, also referred to as saccharides, are basically divided into simple and complex types. The simple carbohydrates are monosaccharides, or the simple sugars such as glucose, which are composed of single chain molecules of sugar.

Complex carbohydrates are made up of di- or polysaccharides, which means that several monosaccharides make up the molecular structure. Simple and complex carbohydrates can be distinguished by taste. Simple carbohydrates are sweet, while the complex types, such as potatoes, are not (Kennedy, 2006).There are other ways of classifying carbohydrates. For example, the Canadian Sugar Institute (1997) classified them into three: sugars, oligosaccharides, and polysaccharides. Carbohydrates supply energy to the body once it is turned into glucose.

When food rich in carbohydrates are ingested, they are broken down into a simple form of sugar, glucose, which is then absorbed by the red blood cells for energy (Kennedy, 1997). It is also the preferred source of energy by the brain, the nervous system, placenta and fetus (United States Department of Agriculture [USDA], 2005, p. 1). When carbohydrates are converted into simple sugar, not all of the sugar is used for energy, and some are stored as glycogen. For athletes or individuals wishing to complete high intensity workout lasting for 90 minutes or more, carbo-loading is essential in order to store more glycogen and thereby enhance stamina and performance (Mayo Foundation for Medical Education and Research. (2004). This, however, is not recommended for people who are only engaging in normal everyday activities.

Carbohydrates are also essential vehicles for micronutrients and phytochemicals, and they are also important in maintaining glycemic homeostatis and for gastro-intestinal function (Canadian Sugar Institute, 1997). They are most beneficial if they are taken from nutrient-rich sources such as fruits and vegetables. Scientists and medical professionals usually differentiate one carbohydrate from another using the glycemic index. This index is based on the comparative increases in the level of blood glucose (sugar) as the carbohydrate-rich food is ingested (Iowa State University Extension, 2003).

Foods with a low glycemic index are digested slowly resulting in a gradual increase in blood sugar. These foods would include high-fiber fruits and vegetables, whole grain products, and legumes. Foods with high glycemic index are easily digested causing a rapid increase in blood sugar. These usually include processed food such as white bread, refined cereal products and candy bars because processing removes the fiber content, which slows down the conversion of carbohydrates into blood sugar. The glycemic index is often used to help balance blood sugar levels in people suffering from diabetes.

However, some dieticians are not satisfied with the use of this index, as it does not address other factors relating to excess intake of sweeteners such as fructose, which registers with a low glycemic index (Wylie-Rosett, Segal-Isaacson & Segal-Isaacson, 2004, p.