Glycemic Index vs Glycemic Load. Why is it important?

Glycemic Index Measures How Quickly A Carb Raises Sugar Levels

Glycemic Index

Glycemic Index is measured on a scale from 1 - 100. Low GI being 55 or less, Medium GI being 56 - 69, High GI being 70+

Some examples: White bread = 75, Apple = 36, Lentils = 32

The major catch here is that Glycemic Index only measures quality NOT the quantity in a serving. GI will not tell you how many grams the carb source has, only how much the carb source will affect you. This is important for many reasons, primarily to regulate your energy throughout the day. Too much sugar and you’ll feel great in moment and tired after digestiong

Glycemic Load

Glycemic Load gives you an idea of a real serving of food and how much it will affect your blood sugar.

Glycemic load = Glycemic Index x grams of carbs per serving / 100.

High GL = 20+, Medium GL = 11 - 19, Low GL = 10 or less

For example, Watermelon Gi ~72 but typically isn’t a lot of carbs with a GL of ~4-6 so it will not significantly spike your blood sugar.

Why is this important for fitness?

Typically we tend to think about fast burning carbs vs slow burning carbs. Like when you’re “Carb loading” for a workout, sitting down for big meals like for Thanksgiving, New Years, or family get togethers. Learning the difference can help you understand what foods to eat and when.

If I’m going for a run, I might want to eat an apple with a bit of peanut butter instead of a pancake with raspberries and maple syrup. While this might sound like an obvious difference for some it’s not obvious for others.

Other reasons for knowing this is if you or a friend or family member is diabetic or pre-diabetic. This information may help you navigate your relationship to them or food better.

Pro Tip

Especially if you’re an athlete, focus on low-GL meals: Whole Foods with fiber, protein, and fat. Combining the right foods here allow for slower digestion; keeping your blood sugar and energy steady.

Check out this extensive and helpful list of foods with attached estimates of Gi and Gl

https://glycemic-index.net/glycemic-index-chart/