The g.i. factor: what our ancestors ateFor 10 000 years, our ancestors survived on a high carbohydrate and low-fat diet. They ate their carbohydrate in the form of beans, vegetables and whole cereal grains. They ate their sugars in fibrous fruits and berries. Food preparation was a simple process: grinding food between stones and cooking it over the heat of an open fire. The result of this process was that all food was digested and absorbed slowly and the usual blood sugar rise was gradual and prolonged. This diet was ideal as far as their bodies were concerned because it provided slow-release energy that helped to delay hunger pangs and provided fuel for working muscles long after the meal was eaten. It was also kind to their pancreas. As time passed, the flours were ground more and more finely and the bran was separated completely from the white flour. With the advent of high speed roller mills in the nineteenth century, it was possible to produce white flour so fine that it resembled talcum powder in appearance and texture. These fine white flours have always been highly prized because they make soft bread and delicious, fluffy sponge cakes. As incomes grew, the legumes and beans commonly eaten by our grandparents were cast aside and meat consumption increased. As a consequence, the composition of the average diet changed: we began to eat more fat and the type of carbohydrate in our diet changed, becoming more quickly digested and absorbed. Something we didn't expect happened, too. The blood sugar rise after a meal was higher and more prolonged, stimulating the pancreas to produce more insulin. So not only did we have higher blood sugar levels after a meal, we had higher insulin responses as well. Insulin is a hormone that is needed for carbohydrate metabolism. But it has a profound effect on the development of many diseases. Medical experts now believe that high insulin levels are one of the key factors responsible for heart disease and hypertension. Insulin influences the way we metabolise foods, determining whether we burn fat or carbohydrate to meet our energy needs and ultimately determining whether we store fat in our body. Thus one of the most important ways in which our diet differs from that of our ancestors is the speed of carbohydrate digestion and the resulting effect on blood sugar and insulin levels. In summary, traditional diets all around the world contained slowly digested and absorbed carbohydrate—foods that we now know have a low G.I. factor (glycaemic index). In contrast, modern diets with their quickly digested fine white flours are based on foods with a high G.I. factor (glycaemic index). *4\33\4* «Online Pharmacy - Levitra» |