One of the most significant ways in which our modern diet differs from that of our ancestors is the speed of carbohydrate digestion and the resulting effect on blood glucose and insulin levels. Medical and nutritional experts now believe that high blood sugar and insulin levels, caused by overconsumption of high-GI carbs in our present-day diet, are one of the key factors responsible for the rise in heart disease and hypertension, diabetes and insulin resistance.
Rise in High-GI Carb Foods
High GI foods are those with a high glycemic index value. The Glycemic Index (GI) is a relatively new measurement of carbohydrate quality – a comparison of carbohydrates based on their immediate effect on our blood glucose (blood sugar) levels. Carbs that metabolize rapidly during digestion (meaning: carbs that are converted to glucose very fast) have high GI values. Carbs that metabolize slowly, releasing glucose gradually into the blood stream have a low glycemic index.
How to Distinguish High GI Carbs From Low GI Carbs
It’s not easy to tell at-a-glance how the carbohydrate in a particular food is ranked on the glycemic index, as there are a number of complex factors that influence GI values. That said, a ballpark guide is the degree of cooking and processing undergone by the carb food in question. So for example, the more swollen or puffed-up, or fluffier the grain, the higher the GI value is likely to be. Whole grain foods (with much of the fiber and germ intact) or raw foods tend to have a lower GI rating. Also, the addition of fat, or the presence of food-acids, tends to lower the GI value.
Modern Dietary Guidelines Flawed
The USDA food pyramid, part of the current US Dietary Guidelines, makes breads, cereals, rice and pasta the baseline daily food, and recommends that we consume 6-11 servings of these items daily. This recommendation has rightly been criticised by nutrition experts at the Harvard School of Public Health for not distinguishing between high and low GI carbohydrates and their relative glycemic responses.
The Value of Exercise in Blood Sugar Control
As any diabetic knows, exercise is a vital element in the effective management and regulation of blood glucose. The fall in physical fitness levels throughout the Western world has undoubtedly contributed to the rise in blood glucose related health problems, including obesity. Exercise enlarges our muscles, makes them more energy-demanding and more sensitive to insulin. As a result, it helps to protect us against the sort of symptoms associated with metabolic ill-health.
