Knowing how different foods affect our blood sugar can be invaluable in our efforts to control our diabetes. We’ve already been told by our doctors that foods high in unrefined carbohydrates can spike our blood sugar and it would be best to avoid them.
Generally, that’s good advice, but how can we identify the foods that have the most negative impact on our blood sugar. It’s not enough to simply tell ourselves to avoid carbohydrate-rich foods. I’m sure most of us already know that eating those chili cheese fries we’ve been craving all day are going to send our blood sugar soaring. We don’t need much help in recognizing that eating those obvious carb-heavy junk foods is not a wise choice. It’s going to have an adverse effect on our blood sugar and wasitline.
But how about those other foods that are supposed to be good for us, but still have a fair amount of carbs in them, like fruits and vegetables? Would enjoying a piece of watermelon on a hot summer day cause our blood sugar to spike? How about munching on some carrots while we watch TV?
It’s probably a good guess that these foods are better for us than a bag of Doritos or some Oreo cookies, but to what degree? And even if they are better for us than those obvious junk food choices, will they still cause a sharp rise in our blood sugar?
Fortunately, we can check the glycemic index and glycemic load of many foods to determine what its impact will be on our blood glucose.
The glycemic index ranks all foods according to how quickly or slowly the carbohydrates in them are broken down and their subsequent impact on raising our blood sugar. Foods with a higher glycemic index would cause a faster and higher spike in blood sugar while foods with a lower glycemic index would be broken down more slowly and have less of an impact on raising our blood sugar.
The glycemic index (GI) ranks foods on a scale of 0 to 100, with a ranking of 100 representing pure glucose. Foods that have a glycemic index rating of 55 or less would be considered to have a low GI score. These would include foods such as walnuts, most vegetables, and mushrooms.
Foods classified as having a GI ranking of 70 or above would be considered to have a high GI score and would include foods like rice, white bread, and most cereals.
But the GI of a food only provides part of the story. The number doesn’t take into account how much of that food is normally consumed in a typical meal. While watermelon has a high GI (over 70) most people would typically not eat a lot of the fruit in one sitting.
To account for this, a glycemic load (GL) rating will factor in what an average person would consume of the food in a typical serving. So whereas watermelon has a high GI (over 70), it has a low GL (under 5). The same could be said for many other fruits like pineapple and cantaloupe. By factoring in what a typical serving of a food would be, the glycemic load index can be more helpful in making food choices.
Taken together, knowing the glycemic index and the glycemic load of a food can help us in assessing how quickly that food will be digested and converted into glucose and released into our bloodstream.
But keep in mind, these are simply tools, not final and definitive answers to how various foods are going to affect us. We are all unique and our bodies will respond differently to different foods, regardless of what its GI or GL is.
While we should certainly incorporate these tools when we consider what foods to eat, the more important measurement to consider when we make our food choices is how our own body responds to it. Testing your blood sugar after meals will still be your best and most accurate indicator of a food’s impact on your blood sugar.
References:
https://www.huffingtonpost.com/riva-greenberg/gl-and-gi_b_863126.html
http://lpi.oregonstate.edu/mic/food-beverages/glycemic-index-glycemic-load
