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CARBOHYDRATE
Carbohydrates are the body's ideal energy source. In fact glucose (a simple carbohydrate) is the primary form of energy used by the brain and central nervous system. Carbohydrates can be divided into two main categories: "simple carbohydrates" and "complex carbohydrates". Simple carbohydrates are sugars such as sucrose (cane sugar), lactose (milk sugar), fructose (fruit sugar), maltose (malt sugar), and glucose. Complex carbohydrates are either starches, glycogens, or dietary fibre. Simple sugars are the building blocks of complex carbohydrates in much the same way that amino acids are the building blocks of proteins. Strictly speaking, all simple sugars are either "monosaccharides" or "disaccharides", and all complex carbohydrates are "polysaccharides".
Monosaccharides such as glucose, fructose, and galactose are the simplest sugars, containing only one sugar molecule each. When a monosaccharide chemically combines with another simple sugar, it forms a disaccharide. Disaccharides include sucrose (a combination of glucose and fructose), and maltose (a combination of two glucose molecules). Polysaccharides are molecular chains of many hundreds or thousands of simple sugars strung together. This complexity is why it takes our digestive system slightly longer to break down complex carbohydrates (compared to sugars). And it is partly why glucose lollies or sugary drinks give you an instant rush of energy, where as starchy foods such as pasta provide slower, more sustained energy. Polysaccharides of plant origin are called "starches"; in animals they are called "glycogens".
When we consume complex carbohydrates our digestive enzymes break down the polysaccharides into disaccharides, and then into glucose which our bodies use for energy. It is this slow release of glucose and the presence of other nutrients such as vitamins and minerals that make comlpex carbohydrates superior to simple sugars. If the glucose in our systems is not immediately needed, it is converted by our liver and muscles into glycogen and stored for later use. Since our bloodstream only holds about one hours supply of glucose, and since the body can only store enough glycogen for half a days needs, carbohydrates must be consumed daily. If our bodies have an excess of glucose, and all of the glycogen storage sites are full, the excess glucose is converted into body fat by the liver and stored for later use.
Foods high in complex carbohydrates include grains such as wheat, rye, rice, and corn; and products made from them such as bread, pasta, and breakfast cereals. Other excellent sources include legumes, root vegetables, and vegetables in general. Health authorities recommend that at least 50% of your total daily energy intake come from complex carbohydrates and another 5-10% from simple sugars (fructose, lactose, etc). One of the benefits of eating a diet high in carbohydrates is the way in which excess glucose (from both complex and simple carbohydrates) is metabolized into adipose tissue (body fat). One quarter of the excess energy we consume in the form of carbohydrates is needed to turn glucose into body fat. This means that only 75% of the actual excess energy is converted into body fat. If the excess energy had been derived from dietary fats, only 3% of it would have been burnt up in the conversion process with the remaining 97% being stored as body fat.
Content & Updated by Reps Mags (MNU)