Glycemic Index 101: What It Is and Why It Matters

Author: By SUSAN BOWERMAN MS, RD, CSSD, CSOWM, FAND, Senior Director, Worldwide Nutrition Education and Training, Herbalife Nutrition.
Vegetables with low Glycemic Index

The glycemic index might be a popular concept, but not one that is easy to grasp. Since it relates to the overall quality of your diet and also has implications for weight management, it is important to understand this concept and how it can help you make better choices.

The glycemic index looks at the effects of carbohydrate-containing foods on sugar levels in your bloodstream. Whenever you eat and digest carbohydrate-rich foods ­– like fruit, vegetables, grains, and sweets – the result is a rise in your blood sugar (blood glucose).

This sugar in your blood is important: it’s the primary fuel for your brain and muscles and is, in large part, what keeps you going mentally and physically throughout your day.

But not all carbohydrate-containing foods cause your blood sugar to rise to the same degree – and this is where the glycemic index (or GI) comes in. The GI ranks foods according to how much and how rapidly they cause the blood sugar to rise after they’re eaten.


What is the Glycemic Index?

Ranks carbs from 0 to 100 according to how much they cause the blood sugar to rise after they’re eaten.

Which Foods Have the Highest Glycemic Index?

Foods that are high on the GI scale are generally low in fibre but are starchy or sugary. Some examples include:

·       White bread

·       Sweet breakfast cereals

·       Noodles

·       Fruit juices

·       White rice

Since these foods are digested and absorbed relatively quickly, they tend to cause large and rapid rises in blood sugar.

A quick spike in your blood sugar is often followed by a steep drop – and suddenly you’re craving something sugary to boost your blood sugar levels back up. And then, the cycle starts all over again.

If you wind up snacking on sugary foods all day long, there’s a good chance you’ll take in more calories than you need.

Which Foods Have a Low Glycemic Index?

The lowest GI foods tend to be carbohydrate-rich foods that are whole and unprocessed. Some examples include:

·       Vegetables

·       Whole fruits

·       Beans

Most 100 percent whole-grain foods like brown rice, rolled oats, barley, quinoa, and 100 percent whole-grain bread have relatively low GI rankings.

Rather than a big spike in blood sugar, these wholesome foods lead to a slower release into your bloodstream, which provides you with more sustained energy.

Using the Glycemic Index to Reduce Your Overall Carbohydrate Load

To cut back on high GI foods and reduce the carbohydrate load of your diet overall, here are some switches you can easily make:

·       Instead of white rice and potatoes, switch to brown rice or other whole grains like cracked wheat, barley, millet, or quinoa. You can also go for beans, lentils or sweet potatoes.

·       Rather than drinking a lot of calories from high GI fruit juices, eat whole fresh fruits

·       Have berries on cereal, or a whole piece of fruit for a snack or dessert.

·       Switch from refined white breads, crackers, and snack foods to products that are made with 100 percent whole grains. Whole and lightly processed low GI foods are bulkier and more filling than their refined cousins, which means they retain their natural vitamins, minerals, and healthy antioxidant phytonutrients, too.

By swapping out the high glycemic index foods and replacing them with more low GI items, you can greatly reduce the overall carbohydrate load of your diet, which can help you with calorie control while providing a healthy nutrient boost.