The glycemic index (GI) is a system for ranking the effect carbohydrates have on blood glucose levels. A consumer study conducted by AC Nielsen in 2005 revealed that 86% of Australians are aware of the significant role of GI and the GI symbol in nutrition and weight LOSS management.
The GI Symbol is used as a way of making a decision to switch to other brands by and incredible 57% Australian shoppers
If a food is low on the glycemic index (low GI) it releases glucose at slower and steadier rates and produces small changes in blood glucose and insulin levels in your body. If a food is ranked as high GI, the opposite is true.
The glycemic index of carbohydrates is classified in three ranges:
· Low GI is 55 or less – includes most fruit and vegetables, whole grains, pasta, beans and lentils.
· Medium GI is 56 to 69 – includes sugar, basmati rice and brown rice.
· High GI is 70 or more – includes corn flakes, baked potatoes, jasmine rice, white bread and candy bars.
Low GI diets have been shown to decrease weight and the risk of disorders such as insulin resistance and Type 2 Diabetes
One recent study evaluated the metabolic effects of meals with varying GI levels on a group of healthy volunteers who ate two different breakfast cereals. The glucose, insulin, and leptin responses of participants were measured after eating.
The participants in the study randomly ate meals in after a 12-hour overnight fast on two separate occasions. The meals consisted of the equivalent of 50 grams of carbohydrate from either Kellogg’s Corn Flakes, or General Mills Fiber One.
Blood samples were taken immediately after eating, and then 30, 60, 90 and 120 minutes later.
The average GI for those who ate Corn Flakes was 125, and for Fiber One eaters it was 49. Corn Flakes are classified as high GI, while the Fiber One is classified as low GI. The insulin response after eating the low glycemic meal was significantly lower compared to the high glycemic food. Participants who ate the Corn Flakes had low levels of leptin in the bloodstream compared to the participants who ate the low glycemic meal.
When considering low glycemic foods look out for the GI Symbol a public health initiative run by Glycemic Index Limited and provides you with a credible signpost to make healthier food choices using the recognised benefits of Glycemic Index and good sound nutrition.