Keep calm and eat your carbs: Why your body needs carbohydrates

Read Time:   |  4th January 2018

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Viva!’s Veronika Charvatova helps you sort out the good carbs from the bad and explains why your body needs carbohydrates... 

Carbs – love or hate them, we all need them. Despite a wealth of low-carb fad diets, there’s no good reason to avoid carbohydrates. The key is in choosing the right ones.

Our cells – every single cell in our bodies – run on carbs.

Your body breaks down carbohydrates into glucose and other molecules, and it’s glucose that is cell fuel. But that’s not an invitation to feast on sugary snacks!

Not all carbs are the same

A carbohydrate is a molecule made up of carbon, oxygen and hydrogen. They can be either simple (sugar) or complex (starch and fibre), depending on how many molecules are bound together, the different types and quantity.

Both simple and complex carbohydrates can be a part of a healthy diet. 

As carbohydrates are digested, they release glucose into the bloodstream. Some foods release it faster. Based on this, a measurement of glucose-release speed has been invented – the glycaemic index (GI).

Foods that release glucose fast have a high GI and are a good source of fast energy – dates, refined cereals, potatoes.

Foods that release it slowly have a low GI and are good for sustained energy release over a longer period of time – most fruit and vegetables, pulses, nuts and seeds.

Then there’s a whole range of foods with a medium GI – wholegrain products, brown rice, porridge. 

Keep calm at eat your carbs: Why your body needs carbohydrates

Simple carbs – sugars

Simple carbs are either single sugar molecules (glucose, fructose) or two sugar molecules linked together (table sugar, milk sugar – lactose).

They are digested fast and we should therefore watch our intake – with the exception of fruit and vegetables.

These naturally contain fructose, a simple sugar, but if eaten fresh and whole they also supply a wealth of complex carbohydrates along with many other nutrients, which slow down the speed of sugar release.

Fruit and vegetables are among the healthiest foods, so there’s no need to limit their intake. They are best eaten raw, lightly cooked or blended in a smoothie, but avoid canned varieties. 

Beware of fruit juices, as they contain almost no fibre and, unless freshly made, undergo a pasteurisation process that destroys most of the goodness.

The result can be little more than sweet water. It’s similar for convenience smoothies – many are mostly juice and have only a fraction of whole fruit in. They’re also pasteurised. You’re better off making your own!

Complex carbs

These consist of many molecules linked together in complex structures and usually mean starch and fibre. The difference is that we can digest starch well, your body breaking it down into single glucose molecules, while we cannot digest fibre.

Starch is naturally a part of many foods, such as wholegrains, pulses, root vegetables, pumpkins, courgettes and so on, all of which belong in a healthy diet. These foods contain starch along with many other nutrients and your body digests them more slowly.

Keep calm at eat your carbs: Why your body needs carbohydrates

On the other hand, refined starches used as a binding agent in foods such as biscuits, processed snacks and sweets, are extracted from natural sources in a process that strips off other nutrients.

This ensures they aren’t very healthy, because you digest them quickly, which may result in high blood sugar levels.

Too much sugar in your blood at any given moment – more than your cells can take up – and your body will try to restore the balance by removing some of the sugar and storing it as fat.

Fibre goodness

Dietary fibre is the name for a large group of complex carbohydrates that we cannot digest. Fibre is naturally found in unrefined plant foods, but never in animal-based foods.

Even though we can’t digest it, it’s an important part of any diet because it keeps the digestive system healthy and improves our energy metabolism by slowing down sugar absorption.

This helps with healthy weight management, can reduce blood cholesterol and the risk of heart disease, some cancers (particularly colon) and diabetes and encourages the ‘good’ bacteria in our gut.

It’s easy to get plenty of fibre from fruit and vegetables, wholegrains, pulses, nuts and seeds. There’s no need to splash on supplements as all you need is in plant wholefoods!

Keep calm at eat your carbs: Why your body needs carbohydrates

There are two types of fibre – soluble and insoluble. Soluble fibre dissolves in water and forms a gel, which can help make you feel fuller for longer after a meal and makes stools soft and easier to pass.

It’s also fermented in the colon by bacteria, resulting in by-products that are beneficial to health. Soluble fibre is therefore a prebiotic – something that promotes beneficial bacteria by providing them with suitable ‘food’ in the intestine.

The best sources of soluble fibre are wholegrains, fruit, pulses and root vegetables. 

The other fibre type is insoluble and it doesn’t dissolve in water, but absorbs it. This means it increases stool bulk and helps keep you ‘regular’. It’s also partially fermented by gut bacteria, which helps the good ones prosper.

The best sources are wholegrains, breakfast cereals, unpeeled fruit and vegetables, nuts and seeds.

How to carb up well

We’ve evolved to thrive on a diet full of natural carbohydrates, so it’s best to build your diet around unprocessed or minimally processed foods, such as wholegrains, fruit and vegetables, pulses (lentils, beans, peas).

These release their energy gradually and promote good health by providing vitamins, minerals, fibre, antioxidants and many important phytonutrients.

On the other hand, processed or refined foods, such as white bread, pastries, processed snacks, cakes, sweets, fizzy and sugary drinks, are full of ‘bad’ carbs that turn into sugar fast.

Like any other junk food, if you have them occasionally, you’re fine, but they shouldn’t be your daily go-to choice.

Our bodies run on carbs, so don’t avoid them. Choose the good ones and you’ll be the best you can be. A steady energy supply from good carbs makes you feel good, physically and mentally.

Healthy fast energy for athletes

During long training or endurance races, athletes often need to replenish energy fast and that means eating fast carbs on the go. The best natural sources are dates, bananas, mashed sweet potatoes and raisins.

These foods help to provide energy to fuel the performance when the body’s own energy stores start running out.

However, if your workouts don’t last longer than 60-90 minutes (depending on intensity), you probably don’t need to worry about it. 

Keep calm at eat your carbs: Why your body needs carbohydrates

Low-carb diets?

Low-carb, ketogenic or paleo diets usually focus on high protein and fatty foods and severely restrict the intake of carbohydrates. This forces your metabolism to change and draw the energy mostly from fat and protein, which makes you less hungry and leads to weight loss.

But – and it’s a big but! – these diets are effective only for short term weight loss and have a range of unpleasant adverse effects such as constipation, headaches, kidney fatigue, bad breath, decreased insulin sensitivity, increased cholesterol levels and more.

In the long term, they are not any more effective for weight loss and maintenance than low-fat diets, which don’t have the nasty side effects and allow your body to function naturally.

Written by

Veronika Charvatova

Veronika Charvátová MSc is a biologist and Viva! Health researcher. Veronika has spent years uncovering the links between nutrition and good health and is an expert on plant-based diets.

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