How Glycemic Index And Glycemic Load Are Calculated - Personal Trainer Explains

As a fitness boot camp owner and Singapore personal trainer, I know that there can be alot of confusion out there about diets and nutrition that help you lose fat and build muscle. Learning about the glycemic load and glycemic index can help you choose foods that will help you reach your fitness, weight loss and muscle building goals.

Ever wanted to know about how we arrive at the Glycemic Index and Glycemic Load of a certain food item? Here's how it's done!

Getting the Glycemic Index value for a food is a slow, painstaking process. Every different item of food is tried and tested on different volunteers and each is done a few times. Thus it takes about 2 days or more to get each value.

The basic steps for all foods are the same.

The first thing that is done is that the volunteer/participant is asked to fast overnight. The next morning, he or she will have 50 grams of white bread, or water into which 50g of glucose has been dissolved. Boths foods are given a value of 100. Blood samples are taken regularly over the following two hours, in order to measure the rise and fall of glucose.

On another day, the same volunteer will fast then eat the test food - beef, potatoes, Cheetos or whatever - enough of that food to get 50g of carbohydrates. Blood samples are then drawn regularly over the next two hours, in order to measure blood glucose levels. The more strongly that food affects blood sugar (and insulin) levels, the higher a value is it given.

The Glycemic index for that food for that particular volunteer is then calculated by dividing the blood sugar response to the test food by the response to white bread of pure glucose.

In order to account for individual differences in how people process food and respond to glucose, glycemic indexes are often the average numbers from 8 to 10 volunteers.

Getting the glycemic load of a food is a little bit simpler. It is the glycemic index multiplied by the amount of carbohydrates actually consumed. For instance, a carrot has 4 grams of carbohydrates and a glycemic index of 131, has a glycemic load of about 5, indicating that carrots don't cause any substantial fluctuations in your blood sugar and insulin levels.

Just think about it - that means that for the volunteers to have ingested 50g worth of carrot-carbohydrates, they had to eat more than a pound of pure carrot!

So remember, if you're using the GI as the main tool for making your healthier food choices, don't forget to check (among other things) the actual amount of carbohydrates in that food!

If there is a food for which you don't know and can't find the GI value for, you can pay for somebody to do the testing for you. Many commercial laboratories nd universities offer glycemic index and/or glycemic load testing services. A quick search on Google will bring up several options.

There we have it, a quick and simple explanation of how GI and GL are calculated. Remember these are important considerations for our personal training and Singapore fitness boot camp clients because it affects their food choices and thus, their fat loss, weight loss and muscle building results.