What is the Glycemic Index All About?

By on April 3, 2013

what is the glycemic indexIn the battle to lose weight, control cravings, and even out blood sugar, you can find hundreds, even thousands of articles and tools that will supposedly help you win. The glycemic index is one of those tools. Now if you’re asking, “what is the glycemic index all about?”you wouldn’t be alone.

Despite the fact that popular diets like South Beach Diet promote it, most people don’t actually understand how the glycemic index works and what it means for your body.

The standard advice goes that you should avoid foods high on the glycemic index. The problem with this though is that merely following that advice can cause the same problems.

So What is the Glycemic Index?

When you eat carbohydrates, the carbs are broken down into glucose. The glucose will be released into the bloodstream eventually. The glycemic index comes into play when analyzing how quickly the glucose is released into the bloodstream and how much enters at a time. Once the glucose hits the bloodstream, your body responds to this rise in blood sugar by releasing insulin to bring everything back into balance.

So what the glycemic index does is provide a measuring point to demonstrate how quickly each kind of carbohydrate becomes pure glucose and reaches the bloodstream. This is distinct from the glycemic load and glycemic response, which then analyzes the carbohydrate levels in relation to the index as well as the body’s insulin response levels.

Foods on the index are ranked from 0 – 100. The higher the food is on the glycemic index, the higher it will raise your blood sugar levels. Zero – 55 is considered low while 56 – 69 is intermediate, and 70 or more is high.

The glycemic index development came about under Dr. David Jenkins, who wanted to understand how different carbohydrates could have different effects on the blood sugar. A slice of chocolate cake, for instance, spikes blood sugar levels far higher than a cup of blueberries.

According to “The Glycemic Index – A Little Bit of History,” the research started a new response to diabetes and blood sugar levels, sparking a focus on good carbohydrates and bad carbohydrates. Many thought that the glycemic index would actually help to resolve the problems with diabetes and perhaps even cure it.

Problems with the Glycemic Index

Unfortunately, the glycemic index, when followed alone, did not have the effect that the medical world hoped. While many foods that aren’t so good for you like Twinkees and fried ice cream are high on the glycemic index, you can’t just follow the index to healthy living.

Well-known author Dr. Joseph Mercola points out one of the biggest issues with the glycemic index as being its lack of reliability and continual exceptions. As he points out in “Glycemic Index Deception Finally Understood,” fructose (a type of sugar) is ranked low on the glycemic index, and yet it is one of the major reasons behind weight gain, inflammation, and a number of health problems.

The glycemic index also fails to account for sucralose, sorbitol, and other aids that make some products low on the glycemic index scale but have been linked to obesity acceleration, cardiovascular disease, and increased sugar cravings.

Another problem is that the basic glycemic index does not monitor the other factors such as the insulin response and the effect on your body. Continuing Dr. Mercola’s point, there are numerous apparent contradictions. Certain fruits, for instance, might rank low on the glycemic index, but fruit juices conversely rank much higher.

This research has been corroborated in “Intake of Fruit, Vegetables, and Fruit Juices and Risk of Diabetes in Women.” Fruit juices, even supposedly health staples like orange juice, can be devastating to your health. And fruit juice isn’t the only so-called health food that can cause problems.

Making Sense of It All

The glycemic index can be rather complicated to work through, particularly when you start trying to figure out whether an exception applies. Instead, it’s much simpler to just avoid most carbohydrate sources like breads, grains, pastas, and sugars. Yes, even fruits should be limited, and you should avoid eating them on an empty stomach.

Where the glycemic index can be useful to you is in analyzing vegetables. Most vegetables rank low on the glycemic index, but a few, like carrots, can be a little higher. As a general rule, your cruciferous and green leafy vegetables are better choices than root vegetables. For those vegetables you are unsure about, you can use the glycemic index for some basis of comparison.

Instead of measuring the GI levels, you can make this far simpler by consuming good lean protein and lots of fresh vegetables. Dropping the sugar and the sugary carbohydrates will do far more for leveling your blood sugar levels.  Thus, you’ll reduce inflammation and other similar ailments rather than try to keep track of each number on the glycemic index.








Johanna Burani, “The Glycemic Index – A Little Bit of History,” Diabetes Health, http://diabeteshealth.com/read/2005/03/01/4238/the-glycemic-indexa-little-bit-of-history/ (2005).

Joseph Mercola, “Glycemic Index Deception Finally Understood,” http://articles.mercola.com/sites/articles/archive/2006/03/23/glycemic-index-deception-finally-understood.aspx (2006).

Lydia A. Bazzano, Tricia Y. Li, Kamudi J. Joshipura, & Frank B. Hu, “Intake of Fruit, Vegetables, and Fruit Juices and Risk of Diabetes in Women,” Diabetes Care, http://care.diabetesjournals.org/content/31/7/1311.full (2008).

About JessicaBFry

Jessica B. Fry has had a passion for writing and health since she was a child. In college, she studied Writing and Pre-Law as a double major before she went on to Regent University to obtain her J.D. She now practices law and works as a freelance writer in rural Indiana where she enjoys being with beloved family, friends, and pets. In her spare time, she works on graphology, writes short stories, and practices knife throwing. She and her husband enjoy exploring Indiana and the surrounding states in their free time and hope to one day complete a trip through every single one.
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