A useful measure, known as the glycaemic index, indicates which foods create a slow, moderate or fast rise in blood-sugar levels. Foods with a high glycaemic rating are quickly broken down into glucose and provide a fast energy fix. Foods with a lower rating take longer to break down and tend to stabilize energy and boost long-term energy stores.
The glycaemic index can be useful in planning diets in special situations: diabetics, for example, need to carefully control their blood-sugar levels, while athletes may need either a fast boost of energy for a sprint or staying power for a long-distance run.
Energy highs and lows
As the glycaemic index shows below, some carbohydrates, when eaten on their own, provide a quick energy boost as the glucose is absorbed from the blood into the cells. Unfortunately, this high is quickly followed by a low that can leave the individual feeling tired and listless. Some people develop sugar cravings and fall into a cycle of glucose highs and lows. To avoid vast swings in energy levels, eat regular meals and spread your carbohydrate consumption as evenly as possible throughout the day. This is particularly important for diabetics, who should take particular care to avoid inconsistent eating patterns. If you are a diabetic, you should always consult your doctor before making dietary changes.
FOODS WITH A HIGH GLYCAEMIC RATING
Most sugary foods including raisins, bananas, honey, jam, glucose, confectionery, chocolate, soft drinks and sweet biscuits; starches such as rice, bread, most breakfast cereals, sweetcorn, cooked carrots, parsnips, potatoes and broad beans.
FOODS WITH A MODERATE GLYCAEMIC RATING
Pasta, noodles, oats, sweet potatoes, yams, crisps, porridge, bran cereals, grapes, oranges and sponge cakes.
Milk, yoghurt, ice-cream, apples, cherries, plums, grapefruit, dates, figs, dried apricots and pulses such as butter beans, baked beans, haricot beans, soya beans, kidney beans, lentils and chickpeas.