Carbohydrates are one of the three important components of the human diet alongside fats and proteins. There are made out of carbon, water and oxygen, brought about by photosynthesis with the help of sun energy and chlorophyll.
Carbohydrates are divided into 3 groups:
The different types of carbohydrates found in foods are all transformed in the body to glucose. The cells can then synthesise other sugars needed for other specific purposes. The carbons are constantly being composed and decomposed in the body.
The Different Functions of Carbohydrates in the Body:
1.) Carbohydrates are the most important source of energy for the body. 1g of carbohydrate provides 4.2 kcal of energy. Almost all of the cells use glucose to distribute energy. The brain cells and the erythrocytes (red blood cells) are completely dependant on glucose as an energy source. If there is too much energy in the body, in the form of carbohydrates, it is transformed into fat and stored in the body. About 30% of the energy is lost when carbohydrates are stored as fat.
2.) Another important function of carbohydrates is to act as energy storage. The body's own glycogen stores act as a readily available energy reserve. A person weighing 70kg has a glycogen reserve of about 350 - 400g, which is about 1.500 kcal. 1/3 of the glycogen is stored in the liver and about 2/3 is stored in the muscles.
3.) Dietary fibres are also carbohydrates. It used to be believed that fibres could not be used by the human body, as the digestive juices in the body did not contain enzymes capable of breaking down these compounds. It was overlooked that a part of the fibre is fermented by enzymes found in the micro- organisms of the large intestines. Found were both gases and short chain fatty acids which can be utilised by the body. The energy gained from fibre (2-3 kcal/g) is negligible as a result of the low amount provided. The recommended consumption by the Govenrment is 30g of fibre a day. The average Britian eats less than the recommended amount.
Recommended Amount of Carbohydrates in the Diet:
There is no precise amount for the intake of carbohydrates. The reason for this is that carbohydrates and fats are able to substitute each other in distributing energy. 60 - 100 g of carbohydrates are necessary for a normal lipometabolism. If the body does not receive enough amounts of energy in the form of fats or carbohydrates, it will begin to break down protein. Carbohydrates are therefore sometimes referred to as having a protein-saving effect.
The government recommends covering at least 50% of the body's energy requirements with carbohydrates.
Starchy, macro-molecular carbohydrates are preferable. The consumption of micro-molecular carbohydrates should be reduced.
Carbohydrates in Foods: