The glycemic index, or GI, of a carbohydrate describes how that food affects blood sugar levels. White bread is used as a reference food on the Glycemic Index Food Chart. You can compare other foods on the chart to see if they will have more or less of an effect on your blood sugar than white bread.
What is the Glycemic Index Food Chart?
The Glycemic Index Food Chart is a list of foods and drinks containing carbohydrates. Each item on the list includes a Glycemic Index Value, or GI, that explains how quickly that food releases glucose into your bloodstream after eating. Foods with a GI level of 55 or less are considered low GI and include mainly fruits, vegetables, nuts and whole grains. Foods such as whole wheat products, basmati rice, potatoes and yams are considered medium GI and have a value between 56 and 69. White bread, white rice, glucose and other foods that are considered high GI have a level of 70 or higher.
Importance of the Glycemic Index Food Chart
High GI foods cause a rapid elevation in blood sugar. This, in turn, leads to your insulin levels to drop so that you feel tired and hungry. Several studies have directly linked high GI foods with obesity. A study published in the "American Journal of Clinical Nutrition" noted that people who eat high GI foods tend to eat more food, while another study published in the 1999 issue of "Pediatrics" found that people who eat high GI foods consume more calories at a meal and are hungrier again sooner than those who eat medium and low GI foods.
White Bread on the Glycemic Index Food Chart
Originally, pure glucose was the reference food on the Glycemic Index Food Chart and had a high GI value of 100. More recently, white bread was also added as a reference food because more people eat white bread and are able to relate to it and compare it to other foods that they eat. White bread also has an arbitrary value of 100. Some glycemic index reference lists, however, actually give white bread a value of 70, with glucose having a GI value of 100.
Alternatives to White Bread
If you are looking to eat foods with lower GI values, you can replace white bread with a wheat tortilla which has a GI value of 30, whole grain bread with a GI value of 51, or pumpernickel with a value of 50. If you still want to eat white bread, you can lower the glycemic value of your meal by adding low GI foods along with your bread including sugar-free peanut butter and hummus. The American Diabetes Association advocated eating high GI foods in combination with low GI foods to balance out the effect of your meal on your blood glucose levels.
References
- American Diabetes Association: The Glycemic Index of Food
- American Journal of Clinical Nutrition; Glycemic Index and Obesity; JC Brand-Miller, et al. July, 2002
- Pediatrics; High Glycemic Index Foods and Overeating in Obese Individuals; DS Ludwig et al. March, 1999
- American Journal of Clinical Nutrition; International Table of Glycemic Index and Glycemic Load Values: 2002; Kay Foster-Powell, et al. July, 2002
- American Diabetes Association: Glycemic Index and Diabetes
- Harvard Health Publications: Glycemic index and glycemic load for 100+ foods
