The Glycemic Index and the Glycemic Load aim to showcase why not all carbohydrates are created equal. Although the Glycemic Index is the more well known of the two, it has its flaws as it does not take into account the amount of a food consumed.
But let’s start from the beginning before I raise even more questions.
What is the “Glycemic Index”?
The Glycemic Index, or GI, measures how fast a specific carbohydrate (e.g. a banana) will convert into sugar (glucose) in your blood. How fast and how high your blood sugar levels will elevate due to eating that food is largely indicative of how much insulin* you will secrete and release. It is significant because if blood sugar rises too quickly, your brain signals your body to secrete a greater amount of insulin. Insulin helps bring sugar out of the bloodstream, primarily by converting the excess sugar into fat and storing it in your body.
A faster increase in blood sugar leads to a greater insulin release and more storage of fat, before a drastic lowering of blood sugar levels occurs. This is what leads to an energy rush followed by lethargy and hunger after eating a candy bar. This process is important because an excess of insulin secretion can result in various ill health effects such as fatigue, weight gain and, eventually, Type II Diabetes.
The GI numbers for each specific food was determined by feeding a group of subjects a carefully measured amount of the tested food (50 grams of carbohydrates). In order to ensure accuracy, the subjects’ blood sugar levels were taken before they ate the food and at different times for several hours after they ate. The results were averaged out and compared to a “reference food”, which is pure glucose (simple sugar). Glucose is ranked 100 and the other foods are given a ranking by comparison.
* Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar levels from getting too high (hyperglycemia) or too low (hypoglycemia).
What is the “Glycemic Load”?
Since a food’s ranking is based on a standardized 50 grams of carbohydrates, a limitation of the glycemic index is that it does not take into account the actual serving you are eating. Let’s take carrots as an example. Carrots have been given a bad rap because of their high GI ranking (74) but, in order to consume 50 grams of carbohydrates from carrots, one would have to eat approximately 50 baby carrots. Yes, if you ate 50 baby carrots your blood sugar would spike, but when would you ever eat 50 baby carrots in one sitting?
Using the glycemic load ranking ensures you are choosing the best carbohydrate options that are based on the actual serving size you are eating. The glycemic load is a way of using the GI rank to make them apply to food as people actually eat them - which is not always 50 grams of carbohydrates!
Calculating the Glycemic Load:
GL = GI rank x serving size of carbohydrates in grams
Can of Coke: .97 x 42g = 40 (Gross!)
Low GL = 10 or less
Medium GL = 10-19
High GL = 20+
Personally, I believe that food should not be broken down into numbers. I believe that when eating a whole foods diet none of the above calculations are really required because whole foods contain the necessary fiber and nutrients to slow down the absorption of glucose into our bloodstream.
In health & happiness,
Website to identify GI and GL foods:
Natalie McCrae R.H.N.
I transform women's body's by teaching them to eat balanced meals so that they can quickly lose weight, without giving up 🍫 & 🍷