Atkins & Low-Carb - Part 4
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)