Carbohydrates

Have you ever heard a particular food described as "healthy" or "unhealthy" and wondered what that's actually based on? When it comes to carbohydrates, the answer is less clear-cut than many people think. Here you'll learn what's behind the different types of carbs and what really matters for your diet.

What are carbohydrates and why do we need them?

Alongside protein and fats, carbohydrates are one of the three macronutrients and form the foundation of a healthy, balanced diet. Put simply, they're sugar compounds that supply your body with energy.

When you hear "sugar", you might immediately think: unhealthy! The reason that's too sweeping a judgement comes down to the difference between the various types of sugar.

Short-chain and long-chain carbohydrates at a glance

Carbohydrates can be grouped by the length of their chains. This is key to how quickly they're digested and how they affect your blood sugar levels.

Short-chain carbohydrates: simple and double sugars

Simple sugars (e.g. grape sugar/glucose, fruit sugar/fructose, table sugar/sucrose) are quick and easy for the body to digest. They provide fast energy, but they also cause blood sugar to rise quickly, and the feeling of fullness doesn't last long.

Double sugars (e.g. milk sugar/lactose, malt sugar/maltose) are also converted into glucose quickly. Their effect on blood sugar and fullness is similar to that of simple sugars. You can recognise both types by their sweet taste.

Long-chain carbohydrates: complex sugars

Complex sugars (e.g. starch and fibre) take longer for the body to break down. That's an advantage: blood sugar rises only gradually, and the feeling of fullness lasts noticeably longer.

Whatever the type, every carbohydrate is ultimately broken down into simple sugar during digestion. So the difference lies mainly in how fast that process happens.

Which carbohydrates are in which foods?

Simple sugars:

• Fruit and vegetables
• Table sugar
• Refined sugar

Double sugars:

• Baked goods
• Sweetened drinks

Complex sugars:

• Potatoes
• Rice
• Oats
• Wholegrain foods
• Legumes

Are there healthy and unhealthy carbohydrates?

Since all carbohydrates are ultimately sugars, and even complex sugars get broken down into simple sugar in the body, it's not that easy to sort them neatly into "healthy" and "unhealthy".

A more useful approach is to judge foods by how much fibre they contain and how rich they are in vitamins and micronutrients. These are exactly the nutrients that give your body far more than just energy.

For a balanced diet, it's worth making sure you're getting enough of these:

• Vitamins and minerals
• Fibre
• Foods that are as unprocessed as possible, which keep you full for longer

The takeaway

Carbohydrates aren't inherently bad or unhealthy. What matters is the choice you make and the amount you eat. Sweets made with table sugar are best kept to a small part of your diet. The focus should be on carbohydrate sources that also provide you with valuable nutrients like micronutrients and fibre. That's why reaching for fruit instead of sweets, for example, often makes more sense.

If you're not sure how to fine-tune your diet, take a look at our healthy eating tips. You'll find plenty of practical ideas for a balanced diet you can actually stick to.