Carbohydrates, sometimes known as just 'carbs', play an important part in our diet through eating starchy foods.
The popularity of low-carb diets may have given carbs a bad name, or at least caused some confusion about whether they are good for us or not. The British Dietetic Association (BDA) says we should get around half our energy intake, or calories, from carbs.
Carbohydrates include sugars and starches that help provide the body with energy and dietary fibre.
Eating too few carbs can lead to low blood sugar levels, called hypoglycaemia, which can make people feel weak or light headed.
The NHS says research shows that most of us should be eating more starchy foods.
All carbs are not equal
Carbohydrates come in different types, and some foods may contain a mixture of different types of carbs. Some people refer to carbs as being 'good' and 'bad'.
Complex carbohydrates are some of the most beneficial or good carbs. Starch is a complex carbohydrate found in cereal, grain, bread, flour, pasta, rice, some fruit and vegetables and breakfast cereal. The BDA recommends wholegrain choices. Complex carbohydrates are also called polysaccharides and contain more than two units of sugar linked together.
Simple sugar or monosaccharide: This carbohydrate has one unit of sugar and is found in fructose or fruit sugar and glucose.
Disaccharide is a carbohydrate containing two units of sugar, such as table sugar or sucrose and milk sugar or lactose.
Non-starch polysaccharides or NSP are carbs like cellulose from the walls of plant cells. Although we cannot digest them, they do make up a major part of dietary fibre.
Potatoes, carrots, root vegetables, pulses, beans and lentils deliver a combination of starches and sugars.
Starchy food and complex carbs also gives the body important vitamins and minerals such as calcium, iron and B vitamins.
Simpler carbs in sugary food, like table sugar, fizzy drinks and sweets contribute very little in the way of other nutrients. They are also often high in calories, so are often seen as bad carbs.
How carbs affect the body
The stomach breaks down carbohydrates and the body absorbs them into the blood at different rates.
In most cases, simple carbs are digested quickly, so blood sugar levels rise faster.
Starchy complex carbohydrates take longer to be broken down and the sugars to be absorbed, so blood sugar levels rise more slowly.
The hormone insulin in the body turns these sugars into the fuel our muscles and brain need.
Any sugars the body doesn’t need straight away are stored by the liver and muscles and ultimately as body fat.
If the body doesn't get enough carbs, it will burn some body fat, which can lead to weight loss. However, eating too few carbs can mean the body eventually looks to heart and muscle tissue to burn.
Eating too few carbs also means the body misses out on important indigestible carbohydrate (dietary fibre), leading to constipation or bowel problems.