The Glycemic Index Explained
Not long ago, we received some pamphlets in the mailbox from the Australian GI Institute to distribute. So this has prompted me to blog on this very important topic – the glycemic index explained.
The Glycemic Index (or GI) rates various foods on how quickly their carbohydrate component is broken down and absorbed into the body. Whilst the “actual” time will vary from person to person, this scale allows us to compare foods in a relative fashion. In other words, one food may be quicker or slower absorbing than other foods.
The scale ranges from 0-100, with glucose having a GI of 100. There are actually a few simple sugars that are absorbed quicker than glucose and they subsequently have a GI of greater than 100.
The GI index is broken down into three categories:
- LOW GI: 55 or less
- MEDIUM GI: 56-69
- HIGH GI: 70 or more
What’s important to note here is that the higher the GI, the faster the carbohydrate will be absorbed into your body. Whilst this has serious ramifications for diabetics, let’s focus on fat loss and gain (considering this is a general health and fitness blog). In order to lose fat, under normal circumstances, it is highly advantageous to consume LOW Glycemic Index foods which take 2-3 hours to absorb (as opposed to high GI which take about an hour). Why? Well this is how I explain it to my clients:
Imagine you have a funnel and are pouring water into it. If you pour the water in slowly, all the water will go through the funnel without spillage. However, if you speed the pouring process up, water will spill over the edge because you are pouring in too much water for the funnel to handle at any one time. The same is true for our bodies. Our body (the funnel) can only handle so many carbohydrates (the water) at any one time. If you pour in too many carbohydrates simultaneously, your blood sugar levels soar, insulin is secreted and all these additional calories overflow, contributing to fat gain.
You can see here that with GI, we are considering the rate of carbohydrate absorption, not the amount of carbohydrate. When rested, your body is far more equipped to handle 50g of carbohydrate over 3 hours than 50g of carbohydrate in 1 hour.
Following an intense workout, you may need additional carbohydrates to facilitate recovery. Carbohydrates are a nutrient and are vital for muscle repair. So it is generally recommended that you consume HIGH GI foods within 2 hours of your workout because that’s when you need a sudden surge of carbs. During the remainder of the day, try to keep your food’s glycemic index relatively low as a general rule.
In our free course, “Conquering Your Body“, we discuss glycemic index in far more detail. We talk about sugars and complex carbs and how GI ties in with it all. If you’re interested in finding out more, I strongly suggest that you sign up!
Plus, be sure to utilise our Food Nutritional Information database where we store a number of foods and their corresponding Glycemic Index.