The Glycemic Index (GI) is a system of ranking the quality of carbohydrate in a food according to the immediate effect it has on blood glucose. Individual foods are compared to pure glucose, which has its Glycemic Index set at 100. For comparison, pearl barley has a value of 33, oranges are 49, and whole wheat bread is 71.
The Glycemic Index was conceived in 1979 by Dr. David Jenkins, together with Dr. Thomas Wolever and Dr. Alexandra Jenkins. The GI breakthrough was the outcome of research conducted at both Oxford University and at the University of Toronto to determine which foods would be best for people with diabetes.
Not all carbohydrate foods are created equal, in fact they behave quite differently in our bodies. The glycemic index or GI describes this difference by ranking carbohydrates according to their effect on our blood glucose levels. Choosing low GI carbs - the ones that produce only small fluctuations in our blood glucose and insulin levels - is the secret to long-term health reducing your risk of heart disease and diabetes and is the key to sustainable weight loss.
The following foods are grouped according to their rating on the glycemic index . The best carbohydrate choices are in the low-glycemic group within the index. Restock the refrigerator and pantry to emphasize low-glycemic foods. Ditch the refined breads and breakfast cereals, baked and mashed spuds, white rice and rice cakes, toaster waffles, tator tots and french fries.
The consumption of high-glycemic foods spikes insulin and reduces glucagon thus preventing the burning of body fat. Try to stay away from high-glycemic foods and stick to lower glycemic choices (see lists below) that will produce less insulin. Insulin stimulates your 30 billion fat cell receptors and deposits carbohydrate energy directly into their interiors, making you fatter and fatter. There is no other way to store fat. Every time you eat a meal, your blood sugar rises. Your goal is to consume the foods (low-glycemic), which will cause the least amount of insulin production.
Any high-glycemic foods should only be consumed in minimum quantities and combined with dietary proteins and fats in a meal. The only exception is a high-glycemic drink after exercise. But remember, even too much of the low-glycemic foods can make you fat.
LOW GLYCEMIC FOODS 20-49 (Your Best FAT WARS Allies)
NUTS AND SEEDS:
All bran cereals
Whole grain pastas
Fresh vegetable juice
Organic plain yogurt (no added sugar)
Low-fat cottage cheese
MODERATE-GLYCEMIC FOODS: Rated 50-69 (LIMIT CONSUMPTION)
Black cherry juice
Corn on the cob
Potatoes (red, white)
Unrefined raw honey
Organic unrefined brown sugar
Unprocessed blackstrap molasses
Organic, grade C maple syrup
Whole wheat bread (100% stone-ground)
Whole grain breads
HIGH-GLYCEMIC FOODS: Rated 70-100 (EAT AT YOUR OWN RISK)
Most dried fruits
and sport drinks
Corn syrup solids
Sucrose (table sugar)
Glucose and glucose
High-fructose corn syrup
Whole wheat bread
Breakfast cereals (refined with added sugar)
Crackers and crispbread
Hamburger and hotdog buns
Muffins (due to the processed flour)
Puffed rice or wheat
How is it tested?
In the two decades since the development of the Glycemic Index, it has been proven repeatedly that the only way to obtain consistent, accurate results is by using blood samples from human subjects and following a precise protocol. Our standard protocol requires that ten normal subjects are studied on multiple occasions in the morning after an overnight fast. After a fasting blood sample, subjects eat the test meal and have further blood samples at 15, 30, 45, 60, 90 and 120 minutes after starting to eat. Capillary blood is obtained by finger-prick. Each subject conducts one trial of each test food and 3 trials of the reference food. The blood is analysed in our laboratory and the incremental areas under the blood glucose curves are calculated using the specified method. The ratio of the test food and the reference food areas gives the GI value.
You are what you eat
This old adage has been proven correct again when it comes to the GI. The original concept was a response to concern for people with impaired insulin responses. Improved stability of blood sugar levels is critical to those people with diabetes, but research has repeatedly shown that stable blood sugar levels have positive health implications for everyone. Diets based on the GI have been shown to stabilize blood sugar, improve body weight, decrease visceral fat, control appetite, improve energy level, enhance memory, balance mood, promote regularity, reduce hospital stay after cardiovascular surgery