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  • Writer's pictureby Eve Lees

Glycemic Index unreliable

Also published in Inspired 55+ Lifestyle Magazine, Nov 24, 2021.

The Glycemic Index (GI) was originally designed for diabetics. It was a method of determining their insulin response to various foods. But, of course, desperate people wanting to lose weight or improve their health ran wild with it. And, not surprisingly, it even became a popular diet.

Now, there is evidence this standard of judging blood sugar/insulin response is not accurate, report nutrition research scientists at Tufts University.

The GI represents the rise in blood sugar levels, two hours after consumption of a food. A value of 100 is the standard, the equivalent amount of pure glucose. Having a rating of 70 to 100 indicates the food is high GI, generating the most severe insulin response. Foods rated 56 - 69 have a medium GI. And foods 55 or less have a

low GI.

However, the Glycemic Index/Load was always highly suspicious, especially given the lack of consistency, from chart to chart, in the varying ratings of certain foods. And common sense tells us we are all unalike in how we react to the foods we eat.

But most troubling is that many people actually omitted certain (healthy) foods because of their high glycemic index. In addition, they prioritized unhealthy foods based on their low glycemic rating. Fortunately, there is now proof this food rating isn't accurate and we should avoid using it to make our food choices.

The Glycemic Index or the Glycemic Load is not an accurate way to judge everyone's reaction to the foods they eat -- or a healthy way to design a diet. And now we have some evidence to support that caution:

Despite the cautions revealed by the Tufts University data, many sources continue to promote the benefits of choosing foods with a low glycemic index and glycemic load value. However, these values will not be reliable in designing a daily food plan, especially for healthy individuals. Although not a perfect method of rating foods, the Glycemic Index can still be a helpful 'tool' for those with Type 2 Diabetes -- as long as it is used sensibly and its inaccuracy is understood.


Eve Lees is a Certified Nutrition Coach, a Health Speaker, and a Health Writer for several publications. The former newspaper editor has also been active in the health & fitness industry for over 35 years.

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