There’s a common misconception that foods that have a high glycemic index (GI) should always be avoided because of their ability to cause a rapid spike in blood sugar and an increased demand on insulin production. Several studies have linked a high-glycemic diet to an increased risk of diabetes, cancer, heart disease and obesity.
While the Glycemic Index number is most widely promoted as an indicator of how healthy or unhealthy a food is, it is actually the Glycemic Load that you should pay attention to, not just the GI.
The Glycemic Index measures the speed at which a certain food raises blood sugar in relation to a control food, either pure glucose or white bread. It is not an accurate measure of how much of a certain food raises blood sugar.
The Glycemic Load, on the other hand, ranks foods based on portion size and grams of carbohydrates per portion. This gives a much more accurate view of how foods might affect blood sugar.
How To Determine Glycemic Load
To find the Glycemic Load of a food, take the number of grams of carbohydrates in a serving, multiply it by it’s Glycemic Index, then divide it by 100 to get the food’s Glycemic Load.
For example, let’s say you have a 1 cup serving of cubed watermelon with 11.5 grams of carbohydrates.
11.5 (grams of carbohydrates) x 0.72 (Glycemic Index divided by 100) = 8.28 (Glycemic Load).
The Glycemic Index of watermelon is 72, which is high, however the Glycemic Load is only 8.28. A Glycemic Load of 10 or less is considered low, while a GL of 11-19 is medium and 20 or more is high.
So you can’t just go by the Glycemic Index number to determine what’s healthy and what’s not. It’s a mistake made many times by health-conscious people who cut the healthiest food on the planet – fruit – out of their diet and with inevitable long-term health consequences.
Enjoy Your Bananas and Watermelons Without Fear
Eating bananas and watermelons are not going to cause diabetes or other blood sugar problems in healthy people as long as your overall dietary fat intake is low.
I think a lot of healthy, non-diabetic people worry too much about blood sugar when a healthy, well-planned diet that includes lots of fruits and vegetables and LOW amounts of fat is not a diabetes risk at all!
(Are you diabetic? Try these green smoothie recipes submitted by readers with type-2 diabetes.)
So go ahead and eat all of the bananas, watermelons and other “high GI” (but low GL) fruit you want. They taste great in green smoothie recipes and will do great things for your health!
Tracy Russell is the creator of the Green Smoothie Health & Weight Loss Program and founder of Incredible Smoothies. She is passionate about helping people improve their health with green smoothies and a whole foods lifestyle.