The LA Times runs an excellent article about low glycemic foods and diets:
Add one more label to the list consumers are increasingly being asked to parse: This one declares food items as “low glycemic,” and refers to a food’s effects on blood sugar levels. Low-glycemic diets have become popular in England and Australia, based on studies that suggest they could help manage diabetes and prevent heart disease and obesity, and they’re now making headway here in the U.S.
What you need to know:
The diet, based on stabilizing blood sugar levels, may help diabetics but its effect on weight loss is harder to determine.