Many of my clients have elevated blood sugar. To measure and control the amount of carbohydrates they eat per meal they use Glycemic Index and Glycemic Load charts. Here is an explanation of these two measurements of foods and how you can apply it in your life.
The Glycemic Index (GI) measures how quickly and how high blood glucose levels will increase after consumption of 50g of food carbohydrate compared to consumption of 50 grams of pure glucose. The higher the GI number, the quicker the carbohydrate will be digested. That will also result in a rapid rise of blood glucose levels. Foods with low GI scores contain carbohydrates that take longer to digest. These foods will raise blood glucose levels slowly and by a limited amount.
Here are GI scores and ranges:
high – 70-100
moderate – 50-70
low – 0-50
Examples of high GI foods are white rice, breads, potatoes, cookies, desserts, corn, and all foods made with flour.
It’s important to note that GI doesn’t take into account regular servings of foods. That makes it hard to apply in real life. For example: GI of beets is 64. That’s for 50 grams of carbohydrates from beets which would require you to eat about 12 cups of beets…. I don’t know many people who can eat that many beets in one sitting!
This is when Glycemic Load can be very helpful.
Glycemic Load (GL) takes into account Glycemic Index AND the normal serving size of foods.
In case you are interested, GL is calculated by multiplying the GI of a food by the number of grams of carbohydrates in a typical serving of that food, divided by 100.
Let’s use our beets to illustrate. Beets have GI of 64 (fairly high) but in a typical serving of 1/2 cup there will only be about 3 grams of carbohydrates. So for a typical serving of beets, GL is less than 2, which is very low.
Here are some examples of GL scores and ranges:
high – 20 and above
moderate – 11-19
low-10 or less
By using foods with a low score on glycemic load AND paying attention to the serving size you can significantly reduce your carbohydrate load per meal and make it a lot easier for your body to handle blood glucose fluctuations.
For instance, back to our breakfast example, eating 3⁄4 cup of Kellogg’s cereal (GL 16) with a glass of skim milk (GL 9) and a glass of orange juice (GL 9) adds up to be a very high glycemic meal (GL 34).
Glycemic Index and Glycemic Load don’t account for other foods that you eat in a meal which is important because total composition of your meal will affect how quickly or slowly it will take you to digest and absorb that meal, skewing the GI and GL of carbohydrates. For example, adding fat to your meal will slow down the digestion and absorption of carbs – which is usually a very good thing.
Also, the GI of a food is calculated as an average response of 10 healthy people. Each individual’s response to food can vary significantly (up to 5-fold) even in a healthy population. Your blood glucose can go 5 times higher than mine when you eat a bowl of ice cream, but my individual response to a bowl of pasta might be 5 times higher than yours.
As you probably appreciate now, applying Glycemic Index and Glycemic Load to your real-world situation can get a bit complicated. If you don’t want to deal with charts of foods and their GI and GL numbers, here is my article on how you can significantly reduce the glycemic load of your diet in a much easier way.