Building a healthy diet: carbohydrates

Carbohydrates play an important role in supplying your body with the energy it needs to carry out normal daily functions. Here are some valuable tips on how you can make carbohydrates part of a healthy diet.

Carbohydrates are found in food as either starches or sugars. Starches, also referred to as complex carbohydrates, are found in breads, breakfast cereals, rice, pasta, and starchy vegetables such as potatoes and corn. This is the type of carbohydrate that supplies your body with the energy it needs.

• Try to limit your intake of refined carbohydrate foods, such as sugar, sweets and cookies. (Carbohydrates can either be refined or unrefined, referring to how much processing the food has gone through.) They'll give you a quick energy boost, but it will quickly fade.
• Choose carbohydrate-rich foods in the form of whole grains, brown rice and legumes, such as chickpeas and kidney beans. They'll give you more energy in the long term than refined varieties, such as white bread, and they contain more essential nutrients.
• Experiment with the variety of whole grains that are now available – millet, rye, buckwheat and rediscovered "ancient" grains such as spelt, kamut, quinoa and amaranth.
• Aim for a serving of dried beans, peas or lentils for lunch or dinner each day or, at the very least, a couple of times a week. Sneak them into family meals: add kidney beans to spaghetti bolognese or mash 250 grams (1 cup) of lima beans and stir it into mashed potatoes or pumpkin.
• Add canned borlotti beans to vegetable or minestrone soup – they boost the fibre content and also provide zinc and iron.
• Snack on fresh, raw sesame, sunflower or pumpkin seeds, or sprinkle them on home-baked muffins. They're also a great garnish for salads, pasta, steamed vegetables or casseroles.

Tip: Don't let any single food – however good for you – dominate your diet, as inevitably it will produce imbalances in the body.

The glycemic index (GI) is a guide devised by nutritionists to identify the rate at which foods break down from carbohydrates to sugar in the blood. Carbohydrates that raise blood sugar more slowly and by a smaller amount are healthier for you in the long term than those that raise it more quickly. Look for the GI symbol on some food packaging. Foods containing carbohydrates are measured on a scale of 1 to 100.

• Choose to eat foods with a low glycemic index (less than 55). They give you a longer lasting source of energy, allowing your blood sugar level to rise and fall gradually.
• Foods that provide slow-burning energy, including legumes, low-fat dairy products, wholegrain breads and breakfast cereals, are better for diabetics and people trying to lose weight. Because low GI foods are digested more slowly, they help you to feel fuller for longer, keeping your hunger under control.
• Eat foods rated high on the index (more than 70), such as potatoes, sugary foods and white bread, before you exercise and you'll experience a fast burst of energy.
• Don't get carried away with GI. The GI value of some healthy foods can be higher than a less nutritious food. For example, 50 grams (1/4 cup) of fresh ripe pineapple has a higher GI than the same amount of chocolate because the fruit contains more glucose. So, while the GI is a valuable tool, always choose foods on the basis of their nutritional value.

By understanding the different types of carbohydrates and the impact they can have on your body, you will be better able to use them as building blocks for a healthy diet.