Glycemic Index

[Raulon Van TassellParticipant]

What is the Glycemic index? Should I use it when I’m considering my food choices?

[JaneParticipant]

According to glycemicindex.com (created by the University of Sydney) glycemic index “Is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. (1)” This scale was originally developed to guide those with diabetes – the lower on the GI scale the better. However, more recent studies have determined low GI foods may be energy dense as well – containing large amounts of sugars and fats that contribute to a diminished glycemic index (2).
Also, the Evidence Analysis Library determined there is “no significance in energy intake or body weight after the consumption of a low glycemic diet.” The academy bases this conclusion off of 8 randomized controlled trails that all report the same thing – a low GI diet will not help you lose weight or lower your energy consumption. Overall, for a healthy person to switch to a low GI diet doesn’t show any benefit (3).
References
1.) University of Sydney. About Glycemic Index. The University of Sydney. 2011. Available at: http://www.glycemicindex.com/about.php
2.) BJ Venn, TJ Green. Glycemic index and glycemic load: measurement issues and their effect on diet-disease relationships. European Journal of Clinical Nutrition. 2007;61:S122-S131. Available at: http://www.nature.com/ejcn/journal/v61/n1s/full/1602942a.html
3.) AND. How effective is the consumption of low glycemic index foods?. Evidence Analysis Library. 2014. Available at: http://andevidencelibrary.com/evidence.cfm?evidence_summary_id=250144

[AshleyParticipant]

That’s a great question! Thank you for addressing this issue! The glycemic index (GI) is used to show “how equal amounts of carbohydrates in different foods raise blood sugar.” (1). In addition, the glycemic load (GL) reflects “both the quality and quantity of carbohydrates in a serving.” (1) Low GI foods (such as brown rice) generally have more complex carbohydrates (starches, fiber) than higher GI foods (such as white rice). These complex carbohydrates get absorbed much slower than simple carbohydrates, which means that your blood glucose levels aren’t being raised as quickly or excessively. (1)

So how do GI and GL affect our health? A review published in the American Journal of Clinical Nutrition observed a multitude of positive effects from low GI diets including “reduce[d] serum lipids in hyperlipidemic subjects, higher HDL-cholesterol concentrations”, and a decreased risk of developing heart disease, diabetes, and certain types of cancer. (2) Other studies agree that low GI diets can help to prevent these issues and may even contribute to increased weight loss/ maintenance, but the results have been mixed (1,3,4). Most research suggests a positive correlation between GI/GL and chronic disease, but more controlled clinical trials need to be administered before dietary recommendations are made. (2,5)

Although the research has not been conclusive, we do know that the lower the GI/GL of the food you consume is, the less dynamic your blood sugar levels will be. In other words, when you ingest more complex carbohydrates and whole grains, you help to keep your blood sugar levels consistent. This plays a role in preventing or delaying certain health complications, especially diabetes and other problems that can arise from high blood glucose levels such as damaged tissues/organs, blindness, kidney failure, and possibly heart disease. (1)

Click link below for a list of the glycemic index and glycemic load for more than 100 common foods! (Reference #6)

 
References

1. NIH. Counting Carbs? Understanding Glycemic Index and Glycemic Load. NIH News in Health. December 2012. Available at http://newsinhealth.nih.gov/issue/Dec2012/Feature2. Accessed April 10, 2014.
2. Glycemic index: overview of implications in health and disease. The American Journal of Clinical Nutrition. 2002:76(1);266S-273S.
3. Dietary Glycemic Index: Health Implications. Journal of the American College of Nutrition. 2009:28(4);446S-449S.
4. Glycemic index, glycemic load, and chronic disease risk—a meta-analysis of observational studies. The American Journal of Clinical Nutrition.2008:87(3);627-637.
5. Glycemic index and disease. The American Journal of Clinical Nutrition.2002:76(1)290S-298S.
6. Harvard Medical School. Glycemic index and glycemic load for 100+ foods. Harvard Health Publications. Available at http://www.health.harvard.edu/newsweek/Glycemic_index_and_glycemic_load_for_100_foods.htm. Accessed April 11, 2014.

• This reply was modified 10 years, 7 months ago by  Ashley.

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