Glycemic Index and Weight Loss
It has been mentioned in media that foods containing low glycemic sugars are beneficial to weight loss, but does the public understand what the glycemic index (GI) is and how it affects weight? This article will briefly explain how the glycemic index operates.
By definition, the glycemic index (GI) is a number given to rank the rate of conversion of carbohydrates to glucose in the body. This is known as the glycemic response, or the food’s ability to raise blood sugar levels (Healthchecksystems.com, 2005). These carbohydrates are given a number between 0 and 100, with pure glucose serving as the reference point for GI at 100 (Nutritiondata.com, 2005). Foods with higher values assigned to them cause the most rapid rise in blood sugar while low index foods tend score very low on the GI. This is not always the case, however, some starches such as potatoes and white bread score even higher than table sugar or honey (Nutritiondata.com, 2005).
So why is the GI so important? The body performs better when the blood sugar levels are held relatively constant (nutritiondata.com, 2005). Not enough glucose and your blood sugar drops causing hunger pangs; too much and the blood sugar spikes causing the brain to signal the pancreas to release more insulin (nutritiondata.com, 2005). Insulin is necessary to regulate the blood sugar; without it one would suffer greatly. However, high insulin levels have demonstrated increases in body fat stores (runningplanet.com, 2005). To regulate the levels, insulin has to store the additional blood sugar in the fat cells. According to runningplanet.com (2005), insulin is 30% more efficient at storing the glucose in fat cells than sending it to the muscles to be burned for energy. To prevent this from occurring, one should eat foods that have a low GI value.
Choosing foods with lower glycemic values will not only reduce blood sugar being stored as fat, but will also increase energy levels by preventing the roller coaster caused by sugar spikes of high glycemic foods (runningplanet.com, 2005). Low GI foods should be consumed before exercise due to slow absorption and provide sustain long-term energy. The best time to consume high GI foods is during or after exercise when the body needs to absorb nutrients quickly. Smart choices should be made to best replenish the body’s stores (healthchecksystems.com, 2005). Below is a list of the GI values of some popular foods.
| High GI >70 | Medium GI >56-69 | Low GI <55 |
|---|---|---|
| White Bread - 96 | Rye Bread – 65 | Pumpernickel Bread – 49 |
| Corn Flakes – 84 | Shredded Wheat – 67 | All Bran – 42 |
| Graham Crackers – 71 | Ice cream – 61 | Yogurt – 33 |
| Dried Fruit – 79 | Blueberry – 59 | Strawberry – 32 |
| Brown Rice – 92 | Refined Pasta – 65 | Vermicelli - 35 |
References
Mendosa, D. (2002). Revised International Table of Glycemic Index and Glycemic Load. Retrieved 03/08/05, from http://diabetes.about.com/library/mendosagi/ngilists.htm.
nutritionaldata.com (2005). Glycemic Index, Glycemic Load, Satiety, and the Fullness Factor. Retrieved 03/08/05, from http://www.nutritiondata.com/glycemic-index.html.
healthchecksystems.com (2005). Glycemic Index and the Glycemic Response. Retrieved 03/08/05, from http://www.healthchecksystems.com/glycemic.htm.
runningplanet.com (2005). The Glycemic Index: How to use it to increase your energy and lose weight. Retrieved 03/08/05, from
http://www.runningplanet.com/articles/articledetail.asp?articleid=430.