Carbohydrates - the role of carbohydrates within the body.
All carbohydrates are primarily molecules of sugar that are used to fuel the body and provide energy. They are basically chemical compounds made up of carbon, hydrogen and oxygen, which join together to form molecules. Simple carbohydrates are single sugar molecules or two sugar molecules that have joined together whereas complex carbohydrates, otherwise known as starches, are comprised of many sugar molecules, which are all connected.
There are three main types of carbohydrates, which are sugars, starches and fibre
, which can all be found in a variety of foods.
What is the function of carbohydrates?
Carbohydrates provide the body with a source of fuel and energy that is required to carry out daily activities and exercise. Any extra energy is stored in the body until it is needed.
Our bodies need a constant supply of energy to function properly and a lack of carbohydrates in the diet can cause tiredness or fatigue, poor mental function and lack of endurance and stamina.
Carbohydrates are also important for the correct working of our brain, heart and nervous, digestive and immune systems.
Fibre, which is also a form of carbohydrate, is essential for the elimination of waste materials and toxins from the body and helps to keep the intestines disease-free and clean.
How do carbohydrates give us energy?
As carbohydrates are digested and broken down by the body, they are converted into glucose (blood sugar), which is then used or stored as energy.
If the glucose is not needed immediately, it will be stored in a person's liver and muscles as glycogen, which is the storage form of glucose.
When the body then needs some extra energy, it will turn to the glycogen reserves and convert them into energy.
What are simple carbohydrates?
Simple carbohydrates are also known as simple sugars and can occur naturally in a food, such as in fruit or they can be broken down and then reformed in an unnatural and manufactured way to produce a product that is high in sugar and usually high in fat.
Simple carbohydrates consist of one or two sugar molecules, which means that due to their simple structure, they can quickly and easily be broken down into glucose and converted into energy very soon after they have been consumed.
However, this causes blood sugar levels (glucose) to rise rapidly, giving a boost of energy, which is quickly followed by a sharp drop of blood sugar levels and therefore a drop in energy levels, which can ultimately leave us feeling more tired than in the first place.
This is true for simple carbohydrates such as sucrose, otherwise known as sugar. Sucrose is the sugar we use to sweeten our hot beverages and it is also present in cakes, pastries, soft drinks and sweets. It is also found in other processed foods, which we may not be aware of.
This type of sugar, the unnatural kind, is what makes us put on weight, not to mention causes tooth decay, mood swings, hunger, lack of concentration, diabetes and hyperactivity, especially in children.
As opposed to natural sugars found in fruit (fructose) and milk (lactose), which do not have the same effect as they contain other substances in them that prevent the glucose being released too quickly into the bloodstream, sucrose is broken down too quickly, which is bad for the body. Our body does not require such a large amount of sugar or energy in one go and only a certain amount can be converted into glycogen and stored for later use, which means that the surplus is then converted into fat. This fat is then virtually impossible to convert back into sugar and use as energy.
Natural sugars found in fruit release energy slowly, contain low levels of sugar and do not contribute to weight gain. They are also high in fibre
What are complex carbohydrates?
Complex carbohydrates are also known as starchy carbohydrates and can be found in most grains, cereals, potatoes, brown rice, bread, pasta, legumes and certain fruits and vegetables.
They are basically many sugar molecules joined together in a chain. Due to the more complex chemical structure, complex carbohydrates are not broken down or digested as quickly or easily as simple carbohydrates.
This is much better for the body, as there are no surges in blood sugar levels and the energy provided from these foods is released at a slow and steady rate, meaning that energy levels should stay more or less the same all day.
Complex carbohydrates are often lower in fat than simple carbohydrates and also contain plenty of vitamins and fibre, which are essential nutrients for the body.
What is the difference between refined and unrefined carbohydrates?
Refined and unrefined carbohydrates are not the same as simple and complex carbohydrates. In simple terms, the former refer to whether or not the product has undergone a chemical process to remove the bran and wheat germ from the grain.
A typical example is bread. White bread has had the bran and germ removed, which turns it into white bread. The same can be said of pasta, rice and sugary cereals.
Many people prefer refined carbohydrates for their taste and texture, however; they have essentially had most of the goodness and natural fibre removed from them.
Unrefined carbohydrates such as wholemeal bread, wholegrain cereals and wholemeal pasta are generally heavier in texture, more filling, more natural, they contain more fibre, vitamins and minerals, leave you feeling fuller for longer, and are definitely healthier for you.
It is always a better choice if you are trying to lose weight and be healthy to choose unrefined carbohydrates as opposed to refined carbohydrates.
Most refined carbohydrates are digested quicker than unrefined carbohydrates and can therefore raise blood sugar levels too quickly.
So, which type of carbohydrates should we eat?
Carbohydrates are an essential part of a healthy diet and should make up 50% of our daily calorie intake. The majority should come from complex carbohydrates, preferably the wholemeal varieties, as well as a large intake of fruit and vegetables.
Simple carbohydrates of the refined kind, including refined sugar (sucrose) should be limited. They have no nutritional value and are generally high in sugars and fats.
To make it really simple:
"Good" carbohydrates are:
Bran, wheat germ, wholemeal bread, brown rice, potatoes, all forms of pasta but especially wholemeal pasta, barley, oats, lentils, chickpeas, beans, peas, corn, sweet potatoes, wholegrain cereals such as Weetabix, muesli, All bran, brown breads, root vegetables such as carrots, turnips, leeks and radishes.
"Bad" carbohydrates are:
Sweets, sugary breakfast cereals, cakes, pastries, syrup, table sugar (sucrose), fizzy drinks, biscuits, chocolate.