Why Glycemic Index and Glycemic Load Matter

Why Glycemic Index and Glycemic Load Matter

Both glycemic index and load start with a key word: “glycemic”.  It refers how much sugar is in foods, and more importantly how it affects your blood sugar levels.

In general, diets that are high on the glycemic index (GI) and high in glycemic load (GL), tend to increase the risk of diabetes and heart disease.

FUN FACT: Starches like those in potatoes and grains are digested into sugar; this is because starch is just a number of sugars linked together. Digestive enzymes break those bonds so that the sugars become free. Then those sugars affect your body the same way that eating sugary foods do.

Glycemic Index

The most common of the two terms is “glycemic index” (GI) or how fast certain foods increase blood sugar levels.

As the name suggests, it “indexes” (or compares) the effect that different foods have on your blood sugar level.

That is because the sugar in them is quickly processed by your digestive system and absorbed into your blood. They cause a “spike” in your blood sugar.

Then each food is given a score from 0 (no effect on blood sugar) to 100 (significant effect on blood sugar). So, you can probably guess that pure glucose is given a GI rating of 100. On the other hand, chickpeas are at a GI of 10.

Regarding GI: low is anything less than 55; moderate is 56-69, and 70+ is considered a high GI food.

Remember, this is a measure of how fast a carbohydrate containing food is digested and raised your blood sugar. It’s not a measure of the sugar content of the food.

How the carbohydrates in food affect your blood sugar level depend on other components of the food. Things like fiber and protein can slow the release of sugar into the bloodstream, and this can make even a high-sugar food, low on the GI scale.

So, lower GI foods are better at keeping your blood sugar levels stable because they don’t increase your blood sugar level as fast.

FUN FACT: Can you guess which food has a GI of higher than 100? (Think of something super-starchy) White potatoes! They have a GI of 111.

Glycemic Load

Glycemic load (GL) doesn’t take into account how quickly your blood sugar “spikes”, but it looks at how high that spike is. Basically, how much the food increases your blood sugar.

GL depends on two things. First, how much of the food is typically eaten. Second, how much sugar is actually in the food.

Low GL would be 0-10, moderate GL would be 10-20, and high GL would 20+.

Example of GL and GI

For example, let’s compare average (120 g) servings of bananas and oranges:

Food GI Serving size (g) GL per serving
Oranges, average 45 120 5
Banana, average 48 120 11

Reference: Harvard Health Publications, Glycemic index and Glycemic load for 100+ foods

As you can see, the orange and banana have almost the same glycemic index. This means they both raise your blood sugar in about the same amount of time.

But, the average orange raises the blood sugar about half as much (GL=5) as a banana (GL=11). So, it contains less overall sugar than the same amount (120 g) of banana.

Of course, this is all relative. A GL of 11 is not high at all. Please keep eating whole fruits.

Impact of GI and GL on your health

Certain people should be aware of the effects that foods have on their blood sugar. People who have diabetes or pre-diabetes conditions like insulin resistance need to be aware of the glycemic index and glycemic load of foods they are eating regularly.

The GI and GL are just two factors to consider when it comes to blood sugar. Some high GI foods are pretty good for you but if you want to reduce the impact on your blood sugar, have them with a high-fiber or high-protein food.


If you have blood sugar imbalances or diabetes, you should probably be aware of the GI and GL of your food.

If you are at risk of diabetes or heart disease, you might try swapping out some higher GI/GL foods and replacing with lower GI/GL foods.

Need help with adding managing your blood sugar? I have a Low Glycemic Program available for you HERE.

Once you purchase the program, it will be delivered to your inbox.

The program includes:

  • 7-Day Meal Plan
  • 17 Recipes
  • Prep Guide
  • Grocery List
  • Daily Nutrition Breakdown

This meal plan is designed to balance your blood sugar levels naturally.

To discuss a more personalized meal plan CLICK HERE to schedule your Discovery Session.

In the meanwhile, try this amazing recipe (with low GI of course!)

Mediterranean Salad (Serves 2)

  • ½ cup chickpeas, drained and rinsed
  • ½ cup cherry tomatoes, halved
  • 1 tbsp apple cider vinegar
  • ¼ cup extra virgin olive oil
  • 1 cucumber, chopped
  • ½ cup black olives
  • ¼ red onion, diced
  • 2 tbsp lemon juice
  • 1 dash black pepper
  • 1 dash sea salt
  • ½ tsp oregano
  • 1 tsp garlic
  • 1 tsp basil


  1. Place first five ingredients together in a bowl.
  2. Add remaining ingredients to a jar (to make the dressing) with a tight-fitting lid and shake vigorously.
  3. Add dressing to salad and gently toss.

Serve & enjoy!

Tip: Add chopped avocado for even more fiber and healthy fat.

In Health,

Dr. Anna ND


  1. Glycemic index for 60+ foods: Measuring carbohydrate effects can help glucose management. http://www.health.harvard.edu/diseases-and conditions/glycemic_index_and_glycemic_load_for_100_foods
  2. Glycemic Index and Glycemic Load. http://lpi.oregonstate.edu/mic/food-beverages/glycemic-index-glycemic-load