What you need to know about the Glycemic Index

Through my discussion with many clients, glycemic index has come up in conversation. I’ve been asked,“What is the glycemic index?”, “Is it helpful?”, and “Why should or shouldn’t I be using it?” To make life easier, I thought I’d spell out some of the answers for you, so here we go!

What is the glycemic index?

The glycemic index is a scale from zero to one hundred that is used to rank carbohydrate containing food items based on how quickly the food causes one’s blood sugar levels to rise. Food items high on the glycemic index will be digested and absorbed quicker, causing blood sugar levels to rise quicker than a food lower on the scale. If you are wondering what a carbohydrate is, check out our previous blog by clicking here!

So what is considered high vs. low glycemic index?

• Low glycemic index: 1 – 55
  • Think of food items like: green vegetables, raw carrots, kidney beans, chickpeas, lentils
• Medium glycemic index: 56-69
  • Think of food items like: sweet corn, bananas, raw pineapple, cherries, whole grain bread
• High glycemic index: 70 and higher
  • Think of food items like: white rice, white bread and potatoes

Why would you consider using the glycemic index?

In practice, the glycemic index may be used when supporting blood sugar control with those with diabetes, pre-diabetes, insulin resistance, or PCOS. You might have also read or heard about it when supporting weight loss.

Are there downfalls to the glycemic index?

Unfortunately, the glycemic index is not a perfect tool. First, the foods are ranked based on the digestion of the food item on an empty stomach. Let’s be real. Most of us do not eat every food item on an empty stomach, if any! Also, the foods on the list don’t include ALL foods, but those foods identified as carbohydrates AND those that have been studied.

Next, we are identifying foods as low, medium and high, but as you might know from working with Chris or I, we can combine food items to slow down digestion and reduce the spike of blood sugars. So even if an item is on the high glycemic index, if paired with a protein or fat source, digestion and absorption
might be slowed down significantly. So just like how we don’t like labeling food as “good” and “bad” maybe we shouldn’t be labeling them as “low” or “high” either.

Lastly, the glycemic index also doesn’t take into account nutrient content. An item high on the glycemic index might be packed with supportive nutrients that our body thrives on! We won’t want to eliminate that just based on this label and would rather find a way to incorporate it into your diet in a healthy,
well-balanced way. Also, the glycemic index does not account for how much of a food item you are eating, which is why the glycemic load was created.

What is the glycemic load?

The glycemic load is a little math equation that helps us combine portion sizes and glycemic index to give us a more accurate number.

So, let’s use couscous as an example. On the glycemic index, couscous is identified as 60 (medium glycemic index), but you are going to eat 1.25 cups of couscous, which has about 45 grams of carbohydrate. For this serving we’d do 45 (grams of carb) x 60 (glycemic index), then divide by 100 to give a glycemic load of 27.

Low glycemic load: 0 – 10
Medium glycemic load: 11-19
High glycemic load: >20

Although this might be high on the glycemic load, or how quickly our blood sugars will rise, we could always eat a smaller portion or pair it with other food items to help our body process it slower.

To sum it up:
After all this, it is best to know that this is a tool and not a black and white guide. It can be referred to, but, is best to use the principles of healthy eating, portion control and carbohydrate counting (when appropriate) to support health, well-being and blood sugar control.

Cheers to more learning!

This blog was written by Amanda J. Stahl RD, LDN, co-founder of Simple Start Nutrition. For more blog posts and nutrition information follow @simplestartnutrition on Instagram and Facebook. Also feel free to contact us, by visiting our website (simplestartnutrition.com) to schedule an appointment to discuss your nutrition related needs. We’re here to help.

References:
https://www.eatright.org/health/wellness/diet-trends/what-is-glycemic-index
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/low-glycemic-index-diet/art-20048478
https://www.mayoclinic.org/diseases-conditions/diabetes/expert-answers/diabetes/faq-20058466