The Role of Carbohydrates
Along with fat and protein, carbohydrates are one of the three most important elements of a balanced diet. Carbohydrates are consumed in many forms in the diet and are the primary source of energy for the muscles and brain. The brain uses carbohydrates, which are broken down into glucose, and cannot use any other type of fuel to properly function. Carbohydrates are also used by working muscles and many other organs of the body, because they are readily available and fast-acting fuels.
How Carbohydrates are Used
Carbohydrates are consumed in food as complex and simple sugars. Complex carbohydrates are simple sugars that are bound together in a chain. A number of digestive enzymes break the bonds between the simple sugars, and they are absorbed through the intestines. Common sources of complex carbohydrates are found in pasta, breads, potatoes, shredded wheat, corn and yams.
Simple sugars are consumed by the body as as glucose, fructose and galactose. Because they are simpler in structure, they tend to be faster-acting sources of carbohydrates. Many start out as disaccharides or polysaccharides until they are broken down to their simplest form.
Circulating as simple sugars, carbohydrates are immediately available to the body as fuel. The brain needs these simple sugars to properly function; when deprived or them, you will feel light-headed, disoriented or just "out of gas." When the body senses a shortage of glucose, it sends a message to the liver to release glucagon, which in turn breaks down stored glycogen (that started out as glucose) and releases glucose into the blood stream.
Carbohydrate as Extra Fuel
If there is a surplus of glucose circulating in the blood, the opposite will occur--the body will store the extra fuel as either fat or "glycogen" in the liver. Examples of simple carbohydrates are apples, lemons, table sugar, candy, soft drinks and even pickles.
