Carbohydrates, Explained

Your body's main fuel, and how to choose the right ones

Carbohydrates are your body's main energy source, especially for your brain and for hard exercise. They are not the enemy. The key is choosing mostly quality sources and matching the amount to your activity.

Simple vs complex

Simple carbohydrates (sugars) digest quickly for fast energy. Complex carbohydrates (starches and fibre) digest more slowly for steadier energy. For satisfying, lasting fuel, base most of your intake on complex, higher-fibre sources like wholegrains, beans, fruit and vegetables.

The glycaemic index, and its limits

The glycaemic index (GI) ranks how quickly a carbohydrate raises blood sugar, and lower-GI foods give steadier energy. But GI has limits: it is based on 50 g of carbohydrate rather than a real portion, ignores the rest of the meal, and everyone responds differently. Use it as a rough guide, not a rule. Combining carbs with protein, fat or fibre slows the rise anyway.

Fibre, the unsung hero

Fibre keeps you full, feeds your gut, steadies blood sugar and supports heart and bowel health. Most of us fall short of the 30 g a day target, so build up wholegrains, beans, fruit, vegetables, nuts and seeds.

Where to learn more: the NHS Eatwell Guide, the British Nutrition Foundation, and the British Dietetic Association (BDA).

This leaflet is general nutritional guidance for education only. It is not medical advice, diagnosis or treatment, and it does not replace advice from your GP or a registered dietitian. Always check with a qualified professional before making significant changes, particularly if you have a health condition, are pregnant, or take medication.