Carbohydrates: They Give Us Energy

Carbohydrates are a class of foods that has different faces:

They sweeten our lives as sugar, but make us fat if we eat too much of them. As starch, they fill us and give us strength and as fibres, they help our digestion.

What kinds of carbohydrates are there and in what are they contained?

You can distinguish between sugars (mono- and disaccharides) made of small molecules and polysaccharides made of giant molecules..

For example, glucose (grape sugar), which can be found in fruits, sweets and honey, and fructose (fruit sugar), contained in fruits and honey, belong to the monosaccharides.

What is commonly called 'sugar' is sucrose, a disaccharide. Sucrose is derived from sugar beet or sugar cane. Other disaccharides are lactose (milk sugar) in milk and maltose (malt sugar) in beer.

Starch, particularly contained in cereals, bread, pasta, potatoes, rice, vegetables (legumes) and bananas, is a polysaccharide. Other polysaccharides are glycogen, which occurs in muscles, and cellulose and pectin, contained in fruits and vegetables.

Our body is only able to utilise glucose directly. All other carbohydrates have to be converted into glucose. Di- and polysaccharides have to be broken down to monosaccharides first.

What does this mean for our alimentation?

Monosaccharides are taken up from the intestine into the blood stream very rapidly and therefore raise the blood glucose level very fast for a short period of time. Because of this, glucose is suitable as an immediate, short living source of energy.

The polysaccharide starch on the other hand, has to be broken down to monosaccharides in several steps by enzymes first, so the monosaccharides are released constantly and slowly into the blood. As a result, starch-rich foods fill you for a longer time. Starch is the most important and best food carbohydrate for us.

The polysaccharides cellulose and pectin can’t be broken down by our body. These indigestible fibres don’t supply energy, but they are important for the peristaltic movement.

What functions do carbohydrates have in the body?

Of all nutrients, carbohydrates are the most important source of energy. 1 gram contains 4 kilocalories of energy. In the body, carbohydrates are stored as glycogen, which is a readily available energy reserve.

In addition, carbohydrates are also important components of body substances like bones, tendons, connective tissue and substances of the blood groups.

How much carbohydrate do we need?

A human needs an average of 250 to 360 g per day. As the most important source of energy, carbohydrates should contribute at least half of the daily needed energy. Fat, which contains more than double the amount of calories, should only make up a smaller share.

The major part of the ingested carbohydrates should consist of polysaccharides. Only small quantities should come from sugars (from sweets, for example). Honey, a mixture of glucose and fructose, by the way, is not healthier than sugar. Very suitable sources of carbohydrates are wholemeal products and vegetables, which generally also contain more fibres and vitamins in addition to the filling vitamins.

If you take in more carbohydrates than your body needs, the surplus will be transformed into fat and stored in the adipose tissue.