Are carbs bad for you? The case for and against

Lesley Dobson / 08 May 2015 ( 16 April 2021 )

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.

Superfood carbs: ancient grains to try

What are carbohydrates?

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

Carbohydrates is a catch-all name that can be further divvied up as follows:

• Fruit sugars – fructose, which as the name suggests, mainly derive from fruits

• Table sugar – sucrose (a combination of fructose and glucose) a carbohydrate that is classed as ‘added’ sugar

• Starches – the main form in which carbs are stored in plants, these are complex carbohydrates, found in potatoes, beans, cereals and grains

• Dietary fibre – a form of carbohydrate found in root vegetables, nuts, seeds, and wholegrain cereals

• Milk sugars – known as lactose (some people cannot digest this).

Why do we need carbohydrates?

They also help us feel full so helping control appetite and calorie intake - and they are vital for a healthy gut.

That said, some carbs will do you more good than others. A plate of deep fried chips, for instance, includes a hefty helping of fat. Treating yourself once in a while is unlikely to do you any harm, but 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, help you avoid constipation and contribute to a healthy gut microbiome. We need 30 grams of fibre a day for long term health.

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 and so on, which can give us those sugar highs – followed by a sudden dip in sugar levels.

As well as 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, as well as vitamins and minerals.

“All fruits are good for you. Try to eat a range of different ones, 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

So long as you are healthy and haven’t been diagnosed with diabetes, it seems that despite numerous claims about the perils of carbs, perhaps it isn’t the carbs that are the problem – rather the type of carbs and the amount we consume.

Do they cause weight gain? Gram for gram carbs actually contain fewer calories than fat (4 cals per gram, around the same as protein, compared to 9 calories per gram for fat).  But of course if you eat too much of anything, especially sugary foods like cakes, biscuits, pastries and sweets, as opposed to higher fibre starchy foods, vegetables, fruit and pulses you’re likely to put on weight.

“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.

So the take home message is: pick the right kind of carbs and don’t overdo them.

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Note:
This advice on carbohydrates is intended for healthy people who do not have type 2 diabetes.  If you do have a diagnosis of diabetes ask to be referred to a NHS Diabetes Specialist Dietitian to get individualised dietary advice on your carbohydrate intake.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.