“High GI”, “Low GI”, “blood sugar spikes”, “blood glucose”, “insulin response”… these phrases get tossed around so much that it can be hard to boil down the biggest takeaways when it comes to the glycemic index (GI). We want to set the record straight and give you some solid ways you can apply this food classification system to your nutrition and your performance!
What is the glycemic index?
At its very core, the glycemic index is a way of ranking carbohydrate-rich foods by how quickly and significantly they raise your blood sugar levels. “Blood sugar” is another way of saying “blood glucose levels.” Low GI foods will absorb more slowly into your body and will have a smaller effect on blood glucose levels and insulin response. This means your energy will be more stable throughout the day. High GI foods will spike your blood sugar quickly and often cause that “sugar crash” later on!
The glycemic index is just that: an index. As the name suggests this is a classification system, which means that all foods need to be measured against a “standard” to determine where they fall on the index.
Some examples of low-GI foods:
- Leafy greens
Some examples of high-GI foods:
- Baked sweet potato
- White rice
- Instant oats
So, at first glance it’s a great way to compare one food to another but if you take a closer look you’ll find that there is more to the story. There are a few limitations to consider.
- Your body’s glycemic response to one food is impacted by the other foods you’ve eat within the same meal. For example, a banana eaten all by itself will impact your blood glucose levels faster than a banana eaten with a tablespoon of peanut butter.
- Food factors like plant variety, ripeness, processing and cooking method can change where a food falls on the glycemic index.
- The time of day and the number of previous meals you’ve eaten can also impact your body’s glycemic response.
- Weight, blood volume and metabolic rate differ greatly between individuals, which will cause the glycemic response to differ as well.
But, as long as you’re aware of where the glycemic index may fall short it can still be a helpful tool.
How the Glycemic Index can be useful to you:
- When it comes to working out and optimizing recovery, eating higher GI foods before/after a training session while limiting the fats you get with that meal will allow your body to utilize these carb sources more quickly.
- When you want a more steady release of energy through the day sticking to lower GI foods will help you avoid that “crash” that comes along with a huge blood sugar spike.
So, even with its limitations, the Glycemic Index can be a great tool. Use it to feel fueled through your daily activities, workouts and recovery!