You already know that some foods affect your blood sugar more than others, but did you know there’s a way to predict how much of an impact different foods will have? These measures are called the glycemic index and glycemic load— let’s dive right in.

What Is Glycemic Index?

Glycemic index indicates how drastically a food will affect your blood sugar by measuring how fast your body will convert a food’s carbs into glucose. The index runs from 1-100 and foods can fall into one of three categories: 

• Low: 1-55

• Medium: 56-69

• High: 70-100

The glycemic index of a food can be influenced by how it’s prepared, its ripeness, its fiber content, and the fat and protein content of the accompanying meal. A food’s score is always based on 50g of carbohydrate of that food.

Typically, less processed foods have a lower glycemic index than processed or refined foods. High glycemic foods are likely to cause a spike in your blood sugar. Over time, this increases your risk of developing diabetes and heart disease.

How Do I Find Out a Food’s Glycemic Index?

Unfortunately, the glycemic index of a food isn’t typically listed on its nutritional label, but you can find glycemic index lists online, including this one from Oregon State University. And– of course– you can always talk to your friendly neighborhood nutritionist!

What Is a Glycemic Load?

A food’s glycemic index and glycemic load are directly connected. Remember, the glycemic index of a food is calculated based on consuming 50g of carbohydrate. However, not all foods have 50g of carbohydrate in a serving size; there are just 12g of carbohydrate in a cup of strawberries and 0.6g in a large egg. This is where glycemic load comes into play. 

Glycemic load is calculated with the formula: (available carbs in a portion size x GI value) / 100

By using a food’s glycemic index and the carbohydrates in a serving, you can estimate how quickly and how much your blood sugar will rise after eating that portion.  

Like glycemic index, foods can have a low, medium, or high glycemic load, but the categories run a little differently. 

• Low: 1-10

• Medium: 11-19

• High: 20 or more

Glycemic load tells us how much digestible carbohydrate is in a food. This matters tremendously because the glycemic index measures the potential impact of a food, but the glycemic load gives you a more accurate picture of what will happen when you eat that food.

For example, previous glycemic index tables have measured the glycemic index of watermelon to be 76, but eating two slices of watermelon provides a low glycemic load of only 6, because it contains little carbohydrate. And while candy– full of sugar– has a high glycemic index, a single bite sized candy bar is going to have a small glycemic load. 

If you are interested in learning more, Diabetes Canada has some really user-friendly information about which foods have high, medium, or low glycemic index scores.

How Can I Use Glycemic Index To Make Healthy Choices?

A food’s glycemic index/load load doesn’t make it inherently healthy or unhealthy. A serving of the ‘superfood’ quinoa has a glycemic load of 13, but a serving of ice cream has a glycemic load of 6. Does that mean that ice cream is the healthier choice? If only! Quinoa is rich in antioxidants and packed with fiber, protein, vitamins, and minerals, whereas ice cream is high in sugar, fat, and calories. 

Knowing the glycemic index or load of food may help you make more mindful, nourishing choices especially if you have a condition that requires extra attention to your glucose levels. Eat to nourish and eat for joy— don’t obsess over these numbers! If you want some help finding that balance that works best for you, I’m here to help you create a plan that satisfies both your taste buds and your body!