Glycemic Index – Bogus or Genius?

The answer is more complicated than you think.

Throughout my 40-week internship, never have I talked about the glycemic index (GI) to any of my patients. And it’s not that the GI is total bogus concept (we’ll get back to that), but it just seems like there was never a right time to talk about it. Introducing this new and foreign notion will just baffle people who are already struggling with their diabetes; in contrast, there is little need to dive into this idea when their diabetes is being well managed. “If it works, don’t touch it,” my supervisor said.

Since I’m not working in the clinical field, I thought I’d ask my fellow dietitian colleagues about how often they make use of GI in their dietary intervention. The answer?

Almost never. (I guess nothing has changed since I graduated.)

With that being said, countless of studies on GI are being published, touting its benefits in the prevention of chronic diseases. Well-established authorities like the Canadian Diabetes Association (CDA) also dedicated a section on GI in their guidelines. However, some health professionals remain skeptical regarding the usefulness and effectiveness of GI on health.

So, should you follow a low-GI diet?




What Is a Glycemic Index?

The glycemic index (GI) is a “scale [1-100] that ranks carbohydrate-rich foods by how much they raise blood glucose (sugar) levels compared to a standard food,” the standard food being glucose or white bread. Foods with a low GI signifies that it will cause a lesser spike in blood sugar after consumption. According to the CDA, consuming low-GI foods offers a wide range of health benefits, including better control over your cholesterol, appetite, and blood sugar levels, and slashing your risk of diabetes and cardiovascular disease.

Glycemic index itself does not serve much purpose, but glycemic load (GL) is slightly better. The glycemic load takes into consideration the amount of carb and is obtained with the following equation: (GI x amount of carb / 100).

glycemic-index

Glycemic Index: Yay or Nay?

In the 2013 CDA Clinical Practice Guidelines, they stated that “teaching a person to use the GI is recommended, but should be based on the individual’s interest and ability.” The American Diabetes Association (ADA) is a bit more conservation, sharing that “using the GI may be helpful in “fine-tuning” blood glucose management,” but that the “the first tool for managing blood glucose is some type of carbohydrate counting.” Much like the ADA, the Academy of Nutrition and Dietetics remains on edge. They criticized GI for not being bestowed a clear-cut definition and that the GI of foods suffers from intra- and inter-individual differences (e.g. age, A1C, body mass index, triglyceride levels), causing the measured GI to be inconsistent. Their Evidence Analysis Library found “no significant effect on A1C trials” and that a “reduction in [GI/GL] alone, without weight loss, may or may not be beneficial” for people at high risk of type 2 diabetes.

Bottom Line

Based on my limited, past clinical experience, I see no use to talk about GI per se to patients – yet. I would say to start applying the traditional, strong dietary interventions before jumping into the GI bandwagon.

[expand title=”References“]

American Diabetes Association. URL Link #1; URL Link #2. Accessed January 27,2017.

Canadian Diabetes Association. URL Link. Accessed January 27, 2017.

Kohn JB. What Do I Tell My Clients Who Want to Follow a Low Glycemic Index Diet? Journal of the Academy of Nutrition and Dietetics.117(1):164.

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