Carbohydrates are made up of one or more units of simple sugars. According to the number of sugar units, they are classified as monosaccharides (1 unit), disaccharides (2 units), oligosaccharides (3-10 units), and polysaccharides (10 to several thousand sugars).
Sugars and starch provide energy, whereas most dietary provides no energy because it passes through the digestive tract and is not absorbed by the body. (A small proportion of fiber is metabolized by bacteria in the large intestine and therefore some energy can be captured for use in our bodies.)
When using term “sugar’” most people think of the refined white crystals commonly called “table” sugar. However, there are many types of sugars found in nature such as fruit sugar and milk sugar. Foods naturally rich in sugars include fruit, vegetables, honey, milk and other dairy products.
Refined starch is also used extensively in the food industry as a thickening agent in processed foods. Many people believe that eating foods containing starch and sugar are “fattening” and that sugar is more fattening than starch. In truth, starch and sugar provide exactly the same amount of energy, so sugar is nor more fattening than starch.
Furthermore, excess body fat is the result of consuming too much food not just carbohydrates. That excess energy intake in any form will cause body fat accumulation, so that excess consumption of low-fat foods, while not as obesity-producing as excess consumption of high-fat products, will lead to obesity if energy expenditure is not increased. Excessive intakes of sugars, which compromise micronutrient density, should be avoided. There is no evidence of a direct involvement of sucrose, other sugars and starch in the etiology of lifestyle-related diseases.
The term “fiber” refers to any plant material that is resistant to digestion and passes though the digestive tract unaltered. In this way, dietary fiber helps to prevent constipation and may lower the risk of colon cancer by speeding up the passage of fecal matter and substances in food that may cause cancer.
Foods rich in complex carbohydrates, including grain foods, vegetables, fruits, and legumes, provide valuable vitamins and minerals and little fat in addition to starch and dietary fiber. A diet rich in complex carbohydrates from these types of food offers many health benefits. A diet rich in complex carbohydrates can help with weight management and prevent heart disease, cancer, diabetes, and intestinal disorders.
One caution is that fiber in the intestinal tract may interfere with the absorption of other essential nutrients although a well-balanced diet including plenty of fluids helps to ensure that all essential nutrients are consumed in adequate amounts.
Carbohydrates in human diet
