The second of the macronutrients is the carbohydrate (CHO). When people hear the word "carbohydrate" or "carbs" they immediately think bread, cereal, etc. Basically anything that contains a grain of some sort. They also include fruits and vegetables. A number of people have been corrected as to what a CHO is.
Also known as sugars, they are organic compounds that contain hydrogen, carbon, and oxygen. There are a variety of sugars, but once consumed, the body converts them to glucose to be used as energy. The sugars that cannot be digested are known as fiber.
CHOs are important because they are the body's primary energy source. This energy can be released immediately or over a period of time depending on the activity involved.
Simple CHO vs. Complex CHO
In the biochemistry world, CHOs are known as saccharides. These saccharides are broken down into the following 4 groups:
- monosaccharides: The simplest CHOs and generally have a sweet taste. Glucose, fructose, galactose are some examples.
- disaccharides: Formed when two monosaccharides are joined together and a water molecule has been removed from the chain. Examples include lactose (galactose + glucose) and sucrose (glucose + fructose). Lactose is found in milk and sucrose is found in sugar cane, beets, bakery products, and soda pop to name a few.
- oligosaccharides: There are a small number of monosaccharides linked together (usually less than 10). The most important component of the oligosaccharide is the disaccharide.
- polysaccharides: They are complex CHOs that are composed of many monosaccharides linked together. Polysaccharides can be used for energy or digestive purposes. They are usually the most abundant CHO found in the diet. Examples include cereal grains, legumes, roots (carrots), tubers (potatoes), and other plant parts.
Some people have heard of simple CHOs and complex CHOs. But what are the differences?
Simple CHOs are the saccharides mentioned in 1, 2, 3 above. They are smaller molecules of sugar that can be easily absorbed into the body's system to be used as immediate energy. The downside to simple CHOs is that if the body's cells do not require the energy that is being consumed, the sugar must be converted to glycogen (stored in muscles or liver) or converted to fat. Most times glycogen stores are well stocked which means the sugar will be converted to fat. Unless you're an endurance athlete or an individual who trains in the anaerobic phase. When the liver is filled to its maximum capacity, the excess glycogen is returned to the blood where is distributed throughout the body for storage. The excess fatty acids tend to get stored in less active areas (buttocks, belly, breasts, thighs) and around active organs such as the heart, kidneys, and previously mentioned liver. Once enough fatty deposits accumulate in and around the organs, they start to slow down thereby reducing their specific responsibilities to the body.
When these simple CHOs are consumed without additional fats or proteins, there is a rise is blood sugar levels. This elevation in blood sugar is an unfavorable environment for the body to be in. Therefore it responds by releasing insulin from the pancreas into the bloodstream. By the time the brain realizes that blood sugar levels are back to normal there is an excess of insulin in the blood. This results in hypoglycemia, or, in laymen's terms, sugar crash. This causes the brain to stimulate the release of a hormone called cortisol from the adrenal glands located on the top of the kidneys. Cortisol causes the liver to release glycogen into the bloodstream to raise the level of blood sugar. Meanwhile, the body is craving some sort of quick energy source to get rid of that fatigued/tired feeling. Therefore people tend to gravitate towards caffeinated beverages (coffee or pop) or eat something sweet. This starts a vicious cycle which causes the body to become less sensitive to insulin leading to something known as Syndrome X, a major first step towards diabetes and other complications. This can be seen by eating "man-made" products such as breads, cakes, pastries, table sugar, cookies, soft drinks, etc. Not good.
Natural foods like fruits and vegetables contain naturally occurring simple sugars. The sugar that is predominant is fructose. With fruits and vegetables the chances of the sugar being converted to fat is much less than the examples mentioned above. This is due to fiber content and fructose being a low-glycemic sugar (to be discussed in the next post). Fructose also has to be processed by the liver before being distributed throughout the body as glucose. Fiber slows the rate of digestion which helps limit the flood of sugar into the blood stream.
Complex CHOs are polysaccharides. As mentioned earlier, they are composed of many simple CHOs bonded together. Digestive enzymes have a more difficult time trying to break down the complex CHOs into simple CHOs for absorption through the intestines. Due to this, there is a slow/steady flow of glucose into the body. This limits the amount of sugar that has to be stored as glycogen or converted to fat and stored.
They are found in grains, fruits, legumes, and vegetables. They also include 3 types of dietary fiber and starches. Starch is mostly found in plants. It contains an indigestible form of CHO known as cellulose or fiber and glycogen, a stored form of CHO found in humans and animals.
Plants store glucose as starch and this starch provides the plant with energy. One starch molecule can contain anywhere from 300 to 1000+ sugar units.
Foods that contain quite a bit of starch include grains (wheat, rice, barley, oats), potatoes, corn, and beans.
If you're interested in finding out how much sugar is in what you consume you can click on the following links:
In Carbohydrates Part 2 the importance of glycemic index and possible side effects of not consuming adequate CHOs will be discussed.
0 comments:
Post a Comment