What is the Glycemic Index and Why Does it Matter?
The term “Glycemic Index” is mentioned frequently in the world of diabetes especially, but what exactly does it refer to?
The Glycemic Index (GI) is a scale which categorizes specific foods and beverages that contain carbohydrates based on how much they increase blood glucose (blood sugar) after consuming them.
There are three categories that these carbohydrate-containing foods and drinks are ranked in. High GI foods or drinks increase blood glucose higher and also faster in comparison to low GI options. Below are the three GI categories organized by GI units:
Low GI Foods (≤ 55 GI units)
Medium GI Foods (56 to 69 GI units)
High GI Foods (≥ 70 GI units)
High GI foods contain more refined carbohydrates and sugars, which are digested quickly and therefore result in a higher blood glucose and increase blood glucose at a faster rate. Low GI foods often have some amounts of fiber, protein, and/or fat, which slows down the digestion process, thereby, increasing blood glucose slowly and resulting in a more stable or lower blood glucose overall. Most carbohydrate-containing foods fit into one of the three categories, however, there are some exceptions when considering ripeness especially in relation to fruit. Bananas, for example, actually fall into all three categories. Why? It’s because bananas vary greatly based on the sugar content or ripeness. So while dark yellow bananas with some browning fall into the high GI group, bananas that have just turned from green to bright yellow are considered medium GI, and green bananas would fall into the low GI group.
What foods or drinks would you expect to find in the high GI category?
– White bread products
– White rice products
– White pasta products
– Instant or refined breakfast cereals
– Starchy vegetables like potatoes
– Sweetened beverages
– Baked goods and snacks like cookies, muffins, chocolate, etc.
What foods or drinks would you expect to find in the low GI category?
– Meat, poultry, and seafood
– Oils
– Nuts and seeds
– Herbs and spices
– Fruits like berries, citrus fruits, and apples
– Non-starchy vegetables like broccoli, cauliflower, and spinach
– Whole grain products like quinoa, couscous, buckwheat, and oats
– Legumes like lentils, chickpeas, and other beans
To see a more complete list of the GI of various foods, you can refer to this guide that lists a variety of other carbohydrate-containing foods and where they fall in the glycemic index categories.
Why is the GI important?
It can be a key tool for promoting better blood sugar management along with other lifestyle and dietary factors. It can also help to create greater awareness of the carbohydrate content of specific foods for more balanced meals. Choosing low GI foods can also help to support weight management and improve cholesterol.
As a final takeaway, there are several factors that impact the GI of foods and drinks like:
– nutrient composition
– ripeness
– how items are cooked or prepared
– the extent of processing that has occurred
Another consideration to remember is that glycemic index is different from glycemic load. The term glycemic load refers to the quantities of carbohydrates and takes into account the amount of carbohydrates in relation to amount of food and the effect this has on blood sugar, while glycemic index does not account for amounts.
If you are looking for more support with choosing lower GI foods or with managing your diabetes, feel free to reach out to us for more individualized nutrition support via our contact us page! Alternatively, we have created an extensive Diabetes Course that is accessible online and self-paced so that you can get all the tools you need to help manage your own diabetes.
Please note this information is for educational purposes only and is not intended as medical advice or individualized nutrition recommendations.
Sources:
1. Diabetes Canada: Glycemic Index Education Portal
2. Harvard Health: Glycemic Index for 60+ Foods
3. Oregon State University: Glycemic Index and Glycemic Load
4. Glycemic Index Food Guide
5. Diabetes UK: Glycemic Load
