Why Carbohydrates Matter
When you hear the word carbohydrates do you think good or bad? For many of us, they’re a natural part of our diet, providing the energy to fuel life – be it heading out on your bike, or simply breathing. But, for others, they are considered the cause of all our fat problems. Some of this is down to the enormous success of the low-carb, high-protein Atkins diet, introduced by Robert Atkins, and the genesis for a whole raft of similar diets.
The trouble is that carbs turn up in all sorts of foods, including fruit and veg, and they’re often an invaluable source of fibre. The confusion lies in the overall term – carbohydrates. Not all carbs are equal – some are good and highly nutritious, some are not so good and some are simply ‘empty calories’.
And when you hear people saying that they are going to cut out carbs from their diet to try to lose weight, or feel less bloated, what they real mean, or should mean, is that they’re cutting out the starchy carbs, such as bread and pasta and highly refined sugary carbs, like cakes and biscuits, rather than all carbs – which would mean cutting out fruit and veg, as well.
What is a carbohydrate?
Carbohydrates are one of three macronutrients (essential food groups) – along with fat and protein – that are found in our food. They are also the body’s primary source of energy. That’s because all carbs – when digested – convert to glucose, essentially the body’s fuel source.
But some carbs are broken down faster than others, which can cause problems. Rapid glucose production creates spikes in your blood sugar levels – it’s the sugar rush from that piece of cake, or biscuit – and the crash is just as fast, often leaving us craving more of those foods.
There are so many terms that explain carbohydrates, which can make the whole thing very confusing; essentially you are looking out for two things – simple, or complex; simple carbs very quickly become sugar and the complex ones – as the name suggests – take longer to convert to sugar, which is kinder on the body’s blood sugar levels.
Your body uses carbohydrates in three main ways:
- Used as immediate energy – carbs are broken down into glucose, which is then absorbed into the bloodstream.
- Unused glucose can be converted to glycogen and then stored in the liver as spare for extra energy requirements.
- Once your body hits its glycogen limit, though, the body starts to convert it into fat for more long-term storage.
Should we be avoiding carbs altogether?
The simple answer is no, but just as with fats and sugar it’s about balance. We get energy from all three main macronutrients but, according to the NHS, the amount varies as follows:
- carbohydrate provides: around 4kcal per gram
- protein provides: 4kcal per gram
- fat provides: 9kcal per gram
The UK government’s healthy eating advice suggests that a little more than a third of our diet should be made up of starchy foods, such as bread and rice, and another third from fruit and veg.
Essentially, we all need carbohydrates in our diet – a study published in 2009 in JAMA Internal Medicine showed that carbs might be important to mental health, with scientists believing that they help to produce serotonin – a key hormone for regulating mood – in the brain. They may help with memory, too. Research at Tufts University in the US in 2008 asked overweight women to completely cut carbs from their diet for a week. Their cognitive skills, visual attention and spatial memory were then tested. The women on the no-carb diet fared worse than those on a low-calorie diet that contained a sensible amount of carbs.
The key is to make good decisions about the carbs that you are eating. We are after the ones that convert glucose and release it into the blood slowly. If too much is released too quickly then our bodies opt for storage, or fat conversion. Choosing wholegrain starchy carbs and fruit and veg are the main ways to ensure you’re eating the most nutritious form, as the body uses them more efficiently and uses the additional vitamins, minerals and fibre. Fibre is crucial in all of this. It’s hard to get enough fibre into your body when you’re on a low-carb diet and, yet, dietary fibre can help you feel full.
One of the biggest problems is that many of us eat too many refined foods – white bread, white pasta, for instance. To understand why, think about a natural grain of wheat, straight from the field. The husk is full of goodness – vitamins, minerals and fibre. However, when a grain is refined – in other words, the husk is removed and only the ‘white’ remains – most of this goodness is lost.
These refined carbohydrate foods are prime culprits when it comes to rapid release of glucose – playing havoc with our blood sugar levels. Eating too much of these foods means we’re really consuming empty calories. The best and easiest solution is stick to the brown stuff.
Choosing the ‘right’ carbohydrates
- All fruit and vegetables, including dried fruit in moderation.
- Wholegrains: brown rice, wholewheat, quinoa, barley, millet, oats, rye
- Pulses and legumes – chickpeas, borlotti beans, butter beans, lentils, split peas, kidney beans, flageolet beans.
Simple carbs – as the name suggests, these are the simplest form of carbohydrate and are made up of one or two sugars that are easy for the body to break down and use quickly. They are found in foods such as white bread, white pasta and many breakfast cereals. In this form they cause a faster rise in blood sugar levels.
Complex carbs – these are the carbohydrates that have many sugar units bonded together and retain their vitamins, minerals and fibre. They are generally found in wholegrain foods, such as brown rice, wholegrain pasta, quinoa, barley, oats. They convert and release glucose slowly into the body.
Refined carbs – grain carbohydrates that have had the wholegrain husk removed, along with other vital vitamins and minerals. The phrase usually refers ‘white’ foods, such as white bread, sugar and white pasta.
Starchy carbs – these are complex carbohydrates, such as pasta, potatoes and rice. To get maximum benefit from these carbs it’s worth switching from white to brown pasta and rice and, where possible, eating potatoes with the skin on.
Fibre –another complex carbohydrate. Can be found naturally in fruit, vegetables, wholegrains and cooked dry beans. Many of us don’t get enough fibre in our diet and we should be looking to eat around 30 grams every day.