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Decoding the Glycemic Index

Understanding the glycemic index (GI) is a powerful tool for anyone living with diabetes. This is because it provides a way to measure how specific foods impact blood glucose levels, allowing for more informed dietary choices.

The glycemic index is a system that ranks foods on a scale of 0 to 100, based on how quickly and significantly they raise blood sugar levels. Foods with a high GI (>70) are rapidly digested and absorbed, causing swift and considerable fluctuations in blood glucose. In contrast,

low-GI foods (<=55) are slowly digested and absorbed, resulting in a gradual rise in blood sugar and insulin levels.

For those with diabetes, controlling blood sugar levels is crucial. Consuming too many high-GI foods can lead to spikes in blood glucose, potentially resulting in hyperglycemia. Conversely, a diet focused on low-GI foods helps maintain steady blood sugar and insulin levels, making diabetes management more achievable.

Incorporating the Glycemic Index into Your Routine

Learning to use the GI involves understanding the values of different foods.

When planning meals:

  • Choose low-GI carbs (<=55): Foods like whole grains, legumes, most fruits, and non-starchy vegetables fall into this category.

  • Balance high-GI foods (>70): If consuming a higher GI food, balance it with low-GI options to moderate the overall GI of your meal.

  • Include protein and healthy fats: These macronutrients aren't scored on the GI but are essential for a balanced meal and can help slow the release of glucose into the bloodstream.

Some more examples of Low-GI food options include:

Grains: Quinoa, sourdough bread, and oatmeal.

  • Fruits: Apples, oranges, and strawberries.

  • Vegetables: Broccoli, spinach, and peppers.

  • Legumes: Hummus, bean dip, and edamame.

However, it’s important to remember that low GI doesn't necessarily mean the food is "healthier." Some low-GI foods can be high in calories or unhealthy fats. On the other hand, another misconception is that all high-GI foods are bad. This is not always true. Fresh watermelon (not watermelon juice), for instance, has a high GI, but its actual glycemic load is low, making it a healthier choice than the GI might suggest. Lastly, it's important to remember that the GI doesn't apply to non-carbohydrate foods. Meats, fats, and oils don't have a GI value but are still crucial components of a balanced diet.

It is also important to recognize that many foods are eaten together, which alters the effects of blood sugar spikes from high GI foods. For example, if a high GI food is paired with a low GI food, high fiber foods, and protein, it might not have the same effect as when eaten alone. All of these considerations are important when preparing meals and selecting what to eat.

The glycemic index can be a valuable tool in your diabetes management toolkit. By understanding its nuances and applying it correctly, it can help you make more informed food choices, better manage your blood sugar levels, and lead to a healthier lifestyle.


  1. Harvard Medical School. (2021) Glycemic index for 60+ foods.

  2. MedlinePlus. (2022). Glycemic Index and Diabetes.


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