The glycemic index (GI) is used to rank carbohydrate-containing foods according to their effect on blood glucose levels after eating. Low GI foods are slowly digested and absorbed and so produce only small fluctuations in blood glucose and insulin levels. By contrast, high GI foods are rapidly digested and absorbed, producing a more pronounced fluctuation in blood glucose levels.
Source: Glycemic Index Foundation http://www.gisymbol.com/about/glycemic-index/
The glycemic index (GI) ranks carbohydrates on a scale from 0 to 100 as follows:
- Low GI foods = GI less than 55
- Medium GI foods = GI between 55 and 70
- High GI foods = GI greater than 70
Health Benefits of a low GI diet
- Reduced insulin levels and insulin resistance.
- Increase HDL cholesterol and reduces LDL cholesterol.
- Protects against cardiovascular disease by reducing inflammation.
- Reduced risk of some cancers by reducing insulin levels.
- Lowers abdominal fat (low GI increases insulin sensitivity which allows you to burn more fat as a fuel source and process your carbohydrates more efficiently).
While low GI is useful when choosing carbohydrate foods it is not necessary to eat only low GI foods to achieve a low GI diet to assist blood glucose control.
- Eating a variety of intact grains, legumes and low GI grain foods lowers the overall GI of your diet.
- Many intact grains are low GI, including oats, rye, barley, quinoa, amaranth, buckwheat, some rice varieties.
- Refined grain foods with a lower GI should be eaten in preference to higher GI varieties. Low GI refined grain foods include sourdough bread, pasta, low GI rice and some breads and breakfast cereals.
- Aim to eat at least one low GI carbohydrate containing food at each meal and base snacks on low GI foods. For example, eating your breakfast cereal with low GI foods like milk, yoghurt, bran or fruit helps to lower the overall GI of the breakfast.