GI stands for Glycemic Index.
(taken from
http://www.glycemicindex.com/)
The glycemic index is a ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels. It compares foods gram for gram of carbohydrate. Carbohydrates that breakdown quickly during digestion have the highest glycemic indexes. The blood glucose response is fast and high. Carbohydrates that breakdown slowly, releasing glucose gradually into the blood stream, have low glycemic indexes.
I am currently getting into following this way of eating and am mostly trying to eat only low GI foods, this is also commonly used by diabetics to control their blood sugar levels and is also a great and healthy way to lose weight and keep it off for life.
Gayle
