Posted by Melissa Seith, RD, LD
You most likely have heard about the glycemic index, but may be wondering what it means or how to use it to improve your own health.
The glycemic index (GI) is a number describing a specific food’s ability to raise blood sugars for every 50 grams of carbohydrate consumed in relation to ingestion of 50 grams of straight glucose. It may seem like the glycemic index would be a simple tool to aid in blood sugar control, but interpreting a GI is a lot more complex than just shooting for a low score, like in a game of golf. There are many other factors that affect your blood sugar response.
First and foremost, it is important to note that the glycemic index is based off of 50 grams of carbohydrate from a specific food — not 50 grams of that food itself.
For example, if you have heard that whole grain bread has a higher glycemic index than a candy bar—it is often overlooked that it takes about 4 oz of whole grain bread (two of our big half inch slice breads) to get 50 grams of carbohydrate whereas it only takes a 2.5 oz Mars candy bar to get those 50 grams. Clearly, it takes a lot more bread to elicit a blood sugar response that is higher than the candy bar. The actual portion size makes a huge difference on the effect a food has on blood sugar. A high glycemic index food can still be healthy if eaten as a normal or smaller portion size.