Since so many people in the United States are currently in the middle of a “carb-frenzy”, this series of articles has focused on the pros and cons of the low-carb diet. Topics of discussion have been 1) Can you stick with a low-carb diet for the long term, 2) Conflicting messages about carbs and 3) bodybuilders and low-carb dieting.
This article will define and describe carbohydrates and what role they play in the human body.
Carbohydrate – Chemical compound of carbon, oxygen and hydrogen, usually with the hydrogen and oxygen in the right proportions to form water. Common forms are starches, sugars, cellulose, and gums. Carbohydrates are more readily used for energy production than are fats and proteins. One of the three basic foodstuffs (proteins and fats are the others), carbohydrates are a group of chemical substances including sugars, glycogen, starches, dextrins, and cellulose. They comprise the body’s main source of raw material for energy. Carbohydrates can be classified as either a simple carbohydrate or a complex carbohydrate.
Digested carbohydrate enters the circulatory system in the form of monosaccharides, primarily glucose. Lesser amounts of fructose and galactose are also absorbed, but these are eventually converted into glucose in the liver. Before they can be absorbed into the bloodstream, polysaccharides and disaccharides must be broken down into monosaccharides by specific enzymes during the digestive process.
When you comsume carbohydrates, your digestive system converts them to blood sugar (glucose). This glucose is stored in your muscle cells and in your liver. Your brain operates with the help of glucose in your blood as energy. When training is intense, glycogen stored within your muscles provides most of the energy for contractions. When training with low intensity, your blood-borne sugar acts as an energy source. A problem occurs when there is leftover glucose in your blood following a refill of carbohydrate stores. The remaining carbohydrates are stored as fat.
There are several types of carbohydrates, some better than others. Starch, sugar and dextrose are all types of carbohydrates. The three main types of carbohydrates are:
* Monosaccharides (one-sugar molecule)
* Disaccharides (two-sugar molecule)
* Polysaccharides (three or more sugar molecules)
Monosaccharides and disaccharides are commonly called sugars, while polysaccharides are called complex carbohydrates or glucose polymers. Some of the more commonly encountered carbohydrates in these three categories include the following:
* Monosaccharides: glucose, fructose, sorbitol, galactose, mannitol, mannose
* Disaccharides: sucrose = glucose + fructose; maltose = glucose + glucose; lactose = glucose + galactose
* Polysaccharides: Starch, dextrin, cellulose and glycogen, all of which are made of chains of glucose. Found in whole grains, vegetables, nuts, some fruits and legumes. Fibers are mainly the indigestible complex carbohydrates (polysaccharides) that make up plant cell walls.
The Glycemic Index is a handy rating system that tells you what carbohydrates provide the best energy for prolonged training periods. By consuming a food with a low glycemic rating, you will experience a more stabilized blood sugar level.
Remember, carbohydrates are your body’s preferred energy fuel source, although fats work well too., particularly during aerobic training. Remember that protein and carbohydrates both have 4 calories per gram, while fat has 9 calories per gram.
SOURCE: (International Sports Sciences Association; Frederick C. Hatfield, Ph.D.; 2001)
* Tracie Johanson is the founder of Pick Up The Pace, a 30-minute exercise studio for women, focusing on fitness, health and nutrition for maximum weight loss. Please visit http://www.letspickupthepace.com/ for more information.