The Glycemic Index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels, and have proven benefits for health. Low GI diets have been shown to improve both glucose and lipid levels in people with diabetes (type 1 and type 2). They have benefits for weight control because they help control appetite and delay hunger. Low GI diets also reduce insulin levels and insulin resistance.
Recent studies from Harvard School of Public Health indicate that the risks of diseases such as type 2 diabetes and coronary heart disease are strongly related to the GI of the overall diet. In 1999, the World Health Organisation (WHO) and Food and Agriculture Organisation (FAO) recommended that people in industrialized countries base their diets on low-GI foods in order to prevent the most common diseases of affluence, such as coronary heart disease, diabetes and obesity.
The GI is simply a dietary tool that helps us differentiate between the various carbohydrate foods we eat and how our bodies use them.
- Carbohydrates with a low GI (55 or less) don’t make our blood glucose levels rise very high for very long. They provide sustained energy. Examples include … pumpernickel, rye, barley, oats, pasta, sweet potatoes, beans, lentils, vegetables, most fruits.
- Carbohydrates with a high GI (70 or more) are the ones that cause our blood glucose levels to go higher for longer. High blood glucose may cause damage to vital organs. Examples include … white & wheat bread, most dry cereals, baking potatoes, watermelon, pineapple.