Carbs: the fast energy food

Carbohydrates have gotten a bad reputation in the media, with many believing too many starches contribute to weight. But carbs are essential to a balanced diet.  The following guidelines will tell you more, including which carbs are best to have.

Our body metabolizes simple carbohydrates and starches into glucose, or blood sugar, the body's primary source of fuel. Carbohydrates are high-quality fuels because — compared to proteins or fats — little is required of the body to break them down in order to release their energy.

Glucose, the only form of carbohydrate that the body can use immediately, is essential for the functioning of the brain, nervous system, muscles and various organs. At any given time, the blood can carry about an hour's supply of glucose. Any glucose that is not need­ed for immediate energy is converted into glycogen, a large molecule composed of a chain of glucose units, which is stored in the liver and muscles. When necessary, the liver turns the glycogen back into glucose. The body can store enough glycogen to last for several hours of moderate activity.

Glycemic index (GI) researchers are learning that the rate at which carbohydrate-rich foods are digested and absorbed into the bloodstream also affects health. The rate at which a food causes blood sugar to rise can be measured and assigned a numerical value. This measure is referred to as the food's glycemic index.

Foods with a low GI such as pumpernickel bread, rye bread, brown rice, bulgur, oatmeal, lentils, yams, apples, pears and yogurt take longer to digest and cause a slower, more gradual rise in blood sugar. This means that energy is released more slowly, leading to more consistent energy levels. Low-GI foods are better for blood sugar control in diabetics and may help with weight loss.

The carbohydrates in high-GI foods such as white bread, white rice, mashed potato, corn flakes and watermelon are more quickly absorbed and so provide a quicker source of energy. For active people, high-GI foods can be a source of quick energy to aid short-duration sports performance and recovery, while lower-GI foods are better for endurance.

When glucose reserves run low, the body turns first to protein and then to fat for conversion into glucose. Burning protein, however, robs the body of lean muscle tissue. In addition, if the body has to burn fat in the absence of carbohydrates, toxic by-products called ketones are released; these can lead to a potentially dangerous biochemical imbalance. Some medical diet clinics take this approach when then promise amazing, fast weight loss results, so be careful before you sign up.

Many people feel that the lower their carbohydrate intake is, the healthier they will be. A great deal of research shows that this is not the case. Choosing the healthiest carbohydrates, especially the whole grains, is important to your well-being. It is well-known that whole grains are important sources of fibre but newer research shows that health benefits can also be attributed to the vitamins, minerals, antioxidants and other plant chemicals found in them.