Carbohydrates are the most important source of energy in the human body. The smallest carbohydrate unit, the sugar, helps power cells, tissue and organs. The more technical name for a sugar is saccharide; in fact, the word saccharide comes from the Greek word meaning sugar. Carbohydrates are made from multiple saccharide units chained together. This can range from two units, in sucrose for example, to the hundreds or thousands of units in starch. The digestive system breaks down these carbohydrates into sugar and absorbs them into the blood. The precise composition of the foods you consume has a large impact on blood sugar. Carbohydrates that break down more slowly release glucose more gradually into the bloodstream.
Complexity of Carbohydrates
In the past, nutritionists have tended to classify carbohydrates into two different categories: simple and complex. Simple carbohydrates such as sucrose were thought to cause higher elevations in blood sugar than complex carbohydrates such as starch. Molecular complexity is one significant factor to consider, but this assumption has proven to be far too simplistic. In reality carbohydrates with similar levels of complexity can vary considerably with respect to their impact on blood sugar.
Glycemic Index
The glycemic index is a numerical scale that measures the rate at which and the degree to which carbohydrates affect blood sugar. The glycemic index number for a carbohydrate is based on how it compares to a reference food or molecule such as glucose. It takes into account such factors as food preparation, storage time, cooking method and the complexity of the carbohydrate. It does not necessarily take into account how foods affect blood sugar in combination with other foods. However, it is generally more accurate than other measurements.
Glycemic Number
Nutritionists assign foods a glycemic index number based on their direct influence on blood sugar. For example, a baked potato has a glycemic index of 76 relative to glucose, which means the blood glucose response to the carbohydrates in a baked potato is 76 percent of the response to pure glucose. Cooked brown rice has a glycemic index of 55 relative to glucose. A carbohydrate with a glycemic index of 70 or above causes a large blood sugar response.
Health Effects
Choosing foods that have a lower impact on blood sugar levels can reduce your risk of insulin resistance, help control your appetite and help prevent obesity and diabetes. According to Dr. Maria Collazo-Clavell on MayoClinic.com, two basic nutritional principles should help you regulate blood sugar. First, eat high-fiber foods such as whole grains, legumes, fruits and vegetables; second, choose fresh or raw foods over canned or processed foods.
