Carbohydrates

Carbohydrates are classified into two kinds:

1. complex carbohydrates (fruits, vegetables, starch and bread products)
2. simple carbohydrates (table sugar, honey, candy, syrup)

Simple Carbohydrates are various forms of sugars (such as sweets and fructose or fruit sugars) that are smaller molecules and easily broken down in the body to be readily available for "quick" energy use. This is why after each time you eat sweets you feel so "perked up" but you also feel so very hungry quickly because that source of energy is used up so rapidly. Complex Carbohydrates (such as wheat and grain products) on the other hand, are larger molecules that are slowly broken down in the body for energy use. However, the type of complex carbohydrates also influence the rate of breakdown into energy use, and therefore, they can also act similarly to Simple Carbohydrates. In general, Carbohydrates also play a very important role in growth, development and maintenance (such as in organs, nerve cells and blood group). The energy content in a gram of Carbohydrates is four (4) calories.

Whatever forms they come in, carbohydrates are converted in the body into energy currency called "glucose or blood sugar". Whether complex or simple - carbohydrates as glucose are used for energy. However, the difference is that complex carbohydrates contain calories, the essential nutrients and fiber. Whereas, simple carbohydrates are referred to as "empty" calories because they do not contain nutrients. A gram of carbohydrate yields 4 calories.

There are several ways the body converts carbohydrates. First, the body converts enough carbohydrates into glucose to use for energy. Then some are stored in the muscles as glycogen. The rest is sent to the liver for storage, also as glycogen. Then the surplus is transformed by the liver into fat to be deposited in fatty tissues around the body. Therefore, the greater the carbohydrate surplus there is, the greater the likelihood of obesity. Overall, the body storage can hold a half day's worth of energy in the form of glycogen that must be converted first back to glucose. The blood system on the other hand, can only hold an hour's supply of glucose. For that matter, hoarding up more than a half day's storage of energy can end up in the fat storage. Likewise , piling up supply of glucose or blood sugar can be dangerous, especially in conditions where the body's ability to utilize sugar efficiently is diminished or ineffective. This is mostly happening in cases of diabetes or glucose intolerance.

Why are carbohydrates important? Carbohydrates are the body's preferred and main energy source. Carbohydrates protect the muscles by sparing proteins and protecting fats from being deprived of their important functions (which we will discuss shortly). When the body needs energy during physical activity, it will look for a carbohydrate source first. If none is available, it will turn to the stored muscle glycogen and break it down as glucose for energy. In contrast, the human brain and the nervous system also need energy, and if that need is not met from a carbohydrate source, the body will break down liver glycogen to reproduce glucose for energy. This is what happens when you have a low carbohydrate diet.

When glucose is no longer available in the body, serious health problems can occur. This means that if glycogen is used up, the body will turn to fat and protein for help, thus depriving them from their important body functions. Fat alone can not remake enough glucose to give energy to the brain and the nervous system. In order to break down fat efficiently, carbohydrate still must be available to help. Without carbohydrate, fat, in an effort to break down its fragments to provide energy, produces excessive amounts of toxic byproducts called ketones. An accumulation of ketones in the blood is called ketosis, which can cause serious consequences, such as coma and even death. This is why severe carbohydrate deficit due to fasting and dieting on a low-carbohydrate diet becomes dangerous.

When the body turns to protein for help, it breaks down the muscle and other protein tissues to reproduce glucose for energy. Important organs, such as the heart and kidneys are made up of muscle tissues. If these tissues continue to be broken down, the result can be fatal. Therefore, carbohydrate intake is important so that glucose is readily available anytime. As nutrition experts have said "there is no better substitute for carbohydrates". That is because carbohydrates have the ability to provide efficient energy as well as protein-sparing functions.

-- Ofelia B. Mutia, M.S.,R.D.,L.D.

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