Carbohydrates in food [replacing lesson: Carbohydrates in food]

To do anything — breathe, think, move around — you need energy. You get this energy from different types of nutrients that are in the food you eat. One of these is carbohydrates. Carbohydrates contain sugars and other molecules that your body can break down into simple sugars. These simple sugars are essential for your cells to function.

There are three main types of carbohydrates: sugars, starches, and fibre. Many people associate carbohydrates with foods like bread, pasta and pastries. But fruits, vegetables and even dairy products all contain them too. Let’s take a look at the three main types of carbohydrates, what foods they turn up in, and how they affect our bodies. We’ll start with the sugars — the simple carbohydrates.

Here is some honey. It is mostly made up of two types of simple sugars — glucose and fructose. Both glucose and fructose are single molecule sugars, or monosaccharides. Like in honey, monosaccharides in foods can be found in their simple form. But in many foods they combine into larger molecules.

For example, a molecule of glucose combined with a molecule of fructose makes a molecule known as sucrose. Sucrose is a disaccharide — that is, two monosaccharides joined together. Sucrose is found naturally in sugar beet and sugar cane and is used to make refined table sugar. Another example of a disaccharide is lactose — a sugar present in dairy products. The body can use simple carbohydrates for energy very quickly because they don’t need to be broken down much.

Glucose can be used directly, and disaccharides only have to be split into two molecules! Because of this, you will feel energised pretty quickly after eating foods high in simple carbohydrates, such as sugary drinks or sweets, but the energy probably won’t last very long. Now here is a potato, some bread, lentils and porridge. All of these are high in another kind of carbohydrate — starch. Starch, unlike sugar, is a complex carbohydrate.

It is a very long chain of glucose molecules. Plants produce this molecule naturally as a way of storing their own food and energy. It takes time for our bodies to break down starch, so glucose is released into the bloodstream slowly. Starchy foods are a great source of steady, rather than quick energy, and they keep you full for a while. Finally, here are some legumes, broccoli, brown rice and whole-wheat flour.

These foods are high in another type of complex carbohydrate — fibre. Fibre is similar to starch in that it consists of long chains of simple carbohydrates. But unlike starch, your body can’t break fibre down into glucose — it can’t digest it. So why do we need fibre in our diet? Eating foods rich in fibre will probably not make you feel energised quickly, but it will keep you full for longer.

It may even prevent or relieve constipation, as it increases the weight and size of the stool, which is then easier to pass. Since different kinds of carbohydrates work differently in our bodies, it is important to get your carbohydrates from a range of sources. This will also ensure you gain other important nutrients at the same time. For example, fruits and vegetables are high in carbohydrates and in essential minerals and vitamins. Legumes are high in fibre and are a great source of protein.

Sweet drinks, pastries and sweets are sources of simple carbohydrates, but apart from sugars, they are not very nutritious — so it might be better to eat them in moderation.