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I entered my 38th year having no idea what the Glycemic Index was, until I became pregnant with my 3rd child.  I was called to the doctor’s office midway through my third trimester to be told that I had gestational diabetes.  In some women, pregnancy causes an insulin malfunction which results in diabetes.  The good news is, the disease goes away immediately after delivery, but it has to be managed until that time.

I tried to convince my doctor that I had been drinking too much lemonade over the summer, and assured her that I would stop (thinking the diabetes would go away if I did), and she chuckled.  “It doesn’t work like that”, she said.

Six weeks, one tiny sliver of pumpkin pie on Thanksgiving, and 192 pokes in my fingers later, I gave birth to a beautiful baby boy, and a newfound knowledge of how what we eat affects our body.

baby with white blanket on his head

Sorry … couldn’t resist!

The Glycemic Index has to do with the consumption of carbohydrates and how they affect our blood sugar.  Carbohydrates are made up of carbon, hydrogen and oxygen (see what they did there with the name?) and they are our primary source of energy, because they break down into glucose when digested.

Carbohydrates include vegetables, fruits, grains, pasta, cereal, bread, sugar, nuts and seeds, and some dairy products.

There are two main distinctions of carbohydrates:  simple and complex.  These distinctions relate to the structure of the carbohydrates and how easy they are to digest.

Simple carbohydrates are digested easily, and when consumed they cause a high amount of sugar to enter the bloodstream very quickly.

Complex carbohydrates take longer to digest, and as a result, they raise blood sugar slowly and gradually.

So, how does this relate to the Glycemic Index?

The Glycemic Index is a listing of all carbohydrates, and each one is assigned a number from 1 to 100 which corresponds to how high they raise blood sugar levels when eaten.  Refined sugar is the highest, at 100, and the numbers come down from there, with the higher numbered ones being simple carbohydrates, and the lower ones being complex carbohydrates.

clipart of glycemic index with simple carbohydrates in red, medium in yellow and complex in green

Okay, well, shoes comes in different sizes, so what?

Well, I guess you could say that if you wear sneakers more than you wear spike heels it will be better for your feet.  But, that doesn’t have much to do with the size!

Here’s the deal.

When we eat any carbohydrate (meaning anything that converts to glucose in the body), our pancreas releases insulin to lower our blood sugar and carry the sugar into our cells so our body can use the glucose for energy.

And in the case of simple carbohydrates, which are digested quickly and easily, this all happens very fast, so our blood is all of a sudden flooded with sugar, and our body responds by releasing a high amount of insulin in order to lower our blood sugar level.

The problem with this is that our body doesn’t have a chance to burn the sugar before the insulin transports it into our cells, and whatever we don’t need is stored as fat.

But, if we eat complex carbohydrates, our blood sugar levels rise more gradually, and as a result, our body releases insulin more gradually too.  So our body has a chance to burn some of our stores of energy to make room for the new stuff the insulin is bringing to our cells.  And the result of this is that less sugar will be stored as fat.

Another drawback of consuming simple carbohydrates is that when our blood sugar spikes very high, very quickly, our pancreas responds by providing a high level of insulin to lower our blood sugar, and then our blood sugar crashes very low, very quickly because of the insulin.  And what happens?  We become hungry again very soon after eating to combat the low blood sugar.  This causes us to crave more food, and once we eat it, the whole process starts again (especially if we eat more simple carbohydrates).  It’s the rollercoaster to end all rollercoasters!

And of course, one of the most severe results of eating a diet loaded with high-glycemic foods, is that our body can develop insulin dysfunction because we are overworking our pancreas (where our insulin is made), which can result in diabetes and very serious complications.

The bottom line is that our body works more efficiently when our blood sugar levels are consistent.

So, taking all of this into consideration, the Glycemic Index is a tool that we can use to help us choose foods that will keep our blood sugar levels more stable.

potatoes in burlap bag

So, are all of the high-numbered foods on the Glycemic Index unhealthy?

No, and this is an important point to note.  There are some items on the Glycemic Index that convert to a high level of glucose when digested, but that have a very high nutrient content.  Two of these are watermelon and potatoes, and potatoes are one of the most nutrient-rich foods on the planet.  See my post here for some of the others.

And lastly, here’s a great article from Diabetes Canada which explains the Glycemic Index in more detail, as well as how we can make better food choices for our health.