In my work as a personal trainer and fitness boot camp owner in Singapore, I frequently get asked questions about the glycemic index and glycemic load. These are great questions, since the glycemic index and glycemic load are useful tools for reaching our fat loss, weight loss, fitness and muscle gain 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. Coming up with each value takes at least two days.
The steps taken for different food item are identical.
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. Then blood samples are taken for the next 120 mins(2 hrs) so blood glucose levels can be evaluated. 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 – , if those volunteers had to eat 50g of carbohydrates from carrot, they actually ate more than a pound of plain, pure carrot in one sitting!
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.
Coach Jonathan Wong, is a sought after Singapore personal trainer and fitness bootcamp owner who has helped hundreds of clients in Singapore achieve their fitness, fat loss and sports performance goals. He Is also a fitness author and a member of Singapore Men’s Health Advisory Panel. Visit his website and blog for frequently, cutting edge health information and a free 1500 page fitness e-book Article Source:
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