Carbohydrates: the case for and against

Lesley Dobson / 08 May 2015

Carbohydrates are often blamed for weight gain, but is it true? We take a look at the pros and cons of carbohydrates and the role they play in your diet.



Believe it or not most carbs are good for us, and a vital part of our diet. They should make up about two thirds of our diet, according to the Government’s advice. One third should be starchy foods, such as wholegrain bread, potatoes and pasta and another third should be fruit and vegetables.

What are carbohydrates?

“Carbohydrates are basically individual sugar units,” explains Elaine Allerton, Dietitian and member and spokesperson for the British Dietetic Association.

“Carbohydrates is the overall heading for this food group, which sub-divides as follows;

  • fruit sugars – fructose, which as the name suggests, comes from fruits
  • table sugar - sucrose, a carbohydrate that is classed as added sugar
  • starches – complex carbohydrates, found in potatoes, cereal and grains
  • dietary fibre – a form of carbohydrates found in root vegetables, nuts, seeds, and wholegrain cereals.”

You also get sugars from milk – known as lactose.

Why do we need carbohydrates?

To start with, carbs are important sources of energy. However, some carbs will do you more good than others. A plate of deep fried chips, for instance, includes a helping of fat. Once in a while it’s unlikely to do you any harm. However, as part of your daily diet, it isn’t a healthy choice.

Tuck into a dish of wholewheat pasta, or a sandwich made with wholegrain bread, on the other hand, and you give your body a helping of healthy carbs that it will convert into the energy you need to keep your body and brain running. You’ll also be having fibre, which will aid your digestive system and help avoid constipation

Find out more about fibre

Carbohydrates that are high in fibre and starch – such as wholegrains, nuts, cereals, give us energy without causing sudden peaks in our blood sugar. This is because they release sugar into our blood more slowly than cakes, biscuits, sweet drinks etc., which can give us those sugar highs – followed by a sudden dip in sugar levels.

As well us being a good source of energy, and fibre, carbs give us vital nutrients. “Fruits are good sources of carbohydrates,” says Elaine Allerton. “Eat the whole fruit, rather than juicing it. That way it gives you soluble fibre, which is important for your digestion, and vitamins and minerals.

“All fruits are good for you. Try to eat a range of different fruit, in lots of different colours – like eating a rainbow. That way you’re more likely to be able to meet all your vitamin and mineral needs.” Eating a wide range of vegetables is important for exactly the same reasons – a variety of nutrients, fibre and carbs.

Find out more about the benefits of eating a rainbow of colourful foods

The downside of carbohydrates

Don’t eat too much of them, is the message. It seems, that despite numerous claims about the perils of eating carbs that perhaps it isn’t the carbs that are the problem, but the amount we consume.

It’s logical that if you eat too much of anything, you’re going to put on weight, because if you take in more energy than you use, that energy will be stored as fat. This applies to carbohydrates as much as it does to protein, fat, and sugar.

“No foods are good or bad, it’s the whole diet that matters,” says Elaine Allerton. “If you eat well 80 – 90% of the time, having some less healthy food some of the time is fine.”

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