Carbohydrates take the form of sugars, starches and fibres and are one of the three major nutrients which supply the body with energy (fat and protein being the others). It is recommended that at least 55% of the calories we eat each day should come from carbohydrates for a healthy balance.
Whereas it is important to maintain an appropriate balance between the number of calories we eat and the number of calories we burn, scientific studies suggest that:
· A high-carbohydrate, low-fat diet may help prevent excess weight gain
· Starch and sugars provide readily accessible fuel for normal brain and body functions and for physical activity
· Dietary fibre, which is a carbohydrate, helps keep the bowel functioning correctly
Apart from these direct benefits of carbohydrates for the body, they are found in a wide range of foods which also contain many other important nutrients. For this reason it is recommended that carbohydrates be supplied from wide variety of foods to ensure that the overall diet contains adequate nutrients. What’s more, carbohydrates contribute to the taste, texture and appearance of foods and help to make the diet more varied and enjoyable.
What are carbohydrates?
The building blocks of all carbohydrates are sugars and they can be classified according to how many sugar units are combined in one molecule.
Glucose and fructose are simple sugars or monosaccharides and can be found in fruits, berries, vegetables and honey. When two simple sugars combine, they form disaccharides. Table sugar or sucrose is a combination of glucose and fructose and occurs naturally both in sugar beet, sugar cane and fruits. Lactose is the main sugar in milk and dairy products and maltose is a disaccharide occurring in malt.
More than 10 and sometimes even up to several thousand sugar units are needed to form polysaccharides. Starch is the main energy reserve in root vegetables and cereals. It comprises long chains of glucose and occurs as granules whose size and shape vary according to the plant in which it is contained. Non-starch polysaccharides are the main components of dietary fibre.
They include: cellulose, hemicelluloses, pectins and gums. Cellulose is the major component of plant cell walls and consists of several thousand glucose units. The different types of dietary fibre have different physical structures and properties.
Energy source and storage
Simple sugars are absorbed directly by the small intestine into the bloodstream, where they are then transported to their place of use. This is why we get an instant energy surge if we eat sweet and sugary foods.
Disaccharides are broken down by digestive enzymes into simple sugars and so take a little longer to absorb. The body also needs the help of digestive enzymes to break down the long chains of starches into their constituent sugars, which are then absorbed into the bloodstream.
It’s best to take carbohydrates in this form since energy is released more slowly. This helps to keeps your energy level up between meals and also helps to curb your appetite.
Thanks to tescodiets.com who have provided this article.