Glycemic index: What it means for you.

 

The glycemic index is a way of measuring the rate at which carbohydrates are broken down and appear in the blood as the simple sugar called glucose. Foods are ranked on the glycemic index scale from 0 to 100, with 100 representing the rate at which pure glucose enters the bloodstream. 

Our cells need glucose for energy, but the amount of glucose in your blood needs to be kept in a very tight range – not too high and not too low. Many organs and systems in the body are damaged when the glucose goes either too high or too low.

The speed at which high-glycemic foods turn to glucose causes the blood sugar to spike high above the normal range. This causes the pancreas to secrete higher levels of insulin, the hormone that controls and transports the glucose into the cells. These high levels of insulin irritate the lining of the capillaries and cell membranes of the muscles, causing them to thicken and eventually become resistant to the insulin. High levels of glucose cause damage to the cells also through inflammation caused by production of “free radicals” – atoms that have lost an electron and consequently “rob” from other atoms, causing a chain reaction called “oxidative stress.”

The high amount of insulin necessary to counteract this abnormally high level of glucose then causes the blood sugar to drop rapidly below the normal blood sugar range. This blood sugar crash stimulates many emergency responses in our body chemistry. The stress hormones adrenaline and cortisol are released producing uncontrollable hunger and cravings, primarily for more high-glycemic foods. This glucose/insulin “roller-coaster” eventually leads to insulin resistance – the muscle cells become resistant to the insulin and therefore can’t absorb the glucose. Instead the insulin transports the glucose to the fat cells (primarily in the abdomen) for storage. Diets full of high-glycemic foods lead to insulin resistance that has been linked to obesity, type II diabetes, and heart disease.

 

HIGH-GLYCEMIC foods rank at 70 or above

[EXAMPLES: most processed foods, most baked goods or breads made from flour, white rice, white potatoes, most breakfast cereals, potato chips, pretzels, candy, table sugar]
High-glycemic foods provide quick energy, but it is usually short-lived and hunger soon returns. Most processed or “convenience” foods and many meal replacement and diet products on the market today are high glycemic. Our diet should include no more than 5 -10 % of these foods, if at all.

 

MEDIUM-GLYCEMIC foods rank from 56 to 69

[EXAMPLES: new potatoes or red potatoes, sweet potatoes, some breads and cereals (cream of wheat, rolled oats), some rice (long-grain, brown, Basmati or parboiled from US), couscous, pasta, fruit juices, pumpkin, sweet corn, taco shells (corn), honey]
Medium-glycemic foods can be used to replace some of the high-glycemic foods (eg., new potatoes instead of white potatoes), but should still be a smaller part of our diet – maybe 20 - 25% of the carbohydrates that we eat.

 

LOW-GLYCEMIC foods rank at 55 or less

[EXAMPLES: most fruits and vegetables, most nuts, beans and lentils, coarse whole grain or sprouted breads, pearled barley, whole kernel wheat or bulgar wheat, parboiled rice (Uncle Ben’s), plain low-fat yogurt, soy milk (unsweetened), skim milk, granulated fructose]
Low-glycemic foods help us feel more satisfied after a meal and provide more sustained energy. Because of their slow digestion and absorption, low-glycemic foods can help control appetite and delay hunger. Low-glycemic foods should make up about 75 - 80% of the carbohydrates we eat.

 

Over 500 nutritional products are compared to an independent nutritional benchmark, developed from the individual recommendations of seven recognized nutritional authorities. Graphical comparisons of over 230 American and Canadian nutritional supplements, along with their Final Product Scores