The Glycemic Index (a.k.a GI) is simply a scale that measures the effects of a food’s carbohydrates on the level of blood sugar in your body. It can be a very useful tool for taking control of your blood sugar, which is a huge factor in obesity and diabetes among other things.

The Glycemic Index is a scale that goes from 0 to 100. The top score of 100 is determined by the amount of blood sugar increase caused by consuming glucose, which is a simple sugar that your body uses as it’s primary source of energy. Naturally, when consumed directly glucose causes the biggest spike in blood sugar and therefore sets the top of the scale.

They do not however take into consideration the quantity eaten when determining the GI score for a particular food. The quantity is accounted for by a different score called the Glycemic Load (total grams of carbs x GI / 100).

There has been extensive research done to develop the Glycemic Index and to find the best ways to benefit from it. Numerous books and papers have been published on it, and it has become an indispensable tool for developing some of the most popular diets around.

Classifications of Glycemic Index

There are three basic classifications of the glycemic index.

  • Low – GI 55 or less – Fruits, vegetables, nuts, some whole grains, etc…
  • Medium – GI 55 to 69 – Whole wheat, brown rice, sweet potatoes, etc…
  • High – GI 70 and above – White rice, white bread, breakfast cereal, etc..
The foods that digest the slowest and take time to absorb have the lowest GI. To lose weight and improve your health, this is what you’re looking to focus most of your diet on.

On the other hand, foods that tend to break down easily are digested quickly and lead to higher spikes in blood sugar levels. Naturally, these are the foods you want to avoid and keep to a minimum in your diet.

The Glycemic Effect

The Glycemic Effect of a food is influenced by numerous variables such as the type of starch in the food, how much fat or protein is also in the food, salt, acid and so on. You can effect the GI of a food by adding vinegar or even by simply combining it with some soluble fiber to slow the digestion process.

Although you can alter the GI this way, it’s still a relative difference. Eating a high GI food is still going to cause a bigger spike than a low GI food even if you try to offset it with added fat or protein, so you’re just better off sticking to the low GI choice.

You want to be careful and not assume a food is low GI. White bread is high GI, so it would make sense to go with wheat, but often times the grain is so processed that they end up with the same score. The crust is often treated with the wrong kind of starch to soften it which raises the GI even further. By choosing a bread made with intact grains and a good hard hearty crust, you’ll have a better chance at getting the GI you’re looking for.

Benefits of Glycemic Index

There has been a lot of research done that shows people who follow a low Glycemic Index diet tend to be considerably healthier than those who do not. They don’t just have healthier waistelines either. They have much better chances at avoiding common modern health problems that range from diabetes to cardiovascular disease and of course obesity.

Following a low GI diet can also help you just plain old feel better. The huge spikes and dips from a high GI diet tend to take their toll on a body. Sticking to the low GI foods will help you feel full for longer, which not only helps keep you from eating too much, but that slow release of food energy will help keep you energized more evenly throughout the day.

There is a labeling system to help you make your GI choices, but just like with any other information be smart about it. Just because something says it’s low GI doesn’t mean it’s good for you nor does it mean you can eat as much of it as you want. There are also some high GI foods that you would want to eat in moderation to get some specific nutrient or at a specific time like right after a workout.

So there you have it. I tried to make it less boring than Wikipedia, but still get the point across, so I hope you have an idea what the Glycemic index is and how you can use it to your advantage. It’s not a prefect system, but it makes another very useful tool to help you decide what to put in the grocery cart.

Now back to my eggplant and spinach on pumpernickle sandwich!
Randy “GI Joe” Lee

The Glycemic Index Lowdown