Beans and Pulses Are Low Glycemic Index Foods
~ April 2008 No.218 ~
The glycemic index is a characteristic of foods that more and more people are looking at when making food choices. For people suffering from diabetes, heart disease or obesity, adding low glycemic index food to the diet may be beneficial.
In its simplest terms, the glycemic index measures how fast food is broken down in the upper gastrointestinal tract. The rate of breakdown can be monitored by measuring blood glucose levels after an individual food has been eaten. In a laboratory setting, subjects who have fasted overnight eat a measured amount of a food and have their blood glucose measured for the next 2-3 hours. A graph is plotted of blood glucose concentration on the y axis vs time on the x-axis. A few days later, the level of blood glucose is measured when the same subject consumes a standard amount of white bread. A second graph can then be plotted for the bread results. Comparing the two glucose curves allows the glycemic index to be calculated. A low glycemic index value means the food is digested more slowly. White bread is given a value of 100 to make comparisons easy. Over time researchers have been able to refine this protocol so that the results are reliable and they have shown that, although the glycemic index is measured on a small number of experimental subjects, the results apply to most consumers.
Foods with a low glycemic index are considered to be healthier because they produce a lower and slower rise in blood glucose. This affects how much insulin the body has to produce during the metabolism of the food sugars, and ultimately affects how much fat is stored in the body. As a group, pulses (peas, chick peas and lentils) and legumes (beans) have low glycemic indexes because of the type of carbohydrates (sugars) they contain. Although these foods are well known to people around the world, they are not so popular in North America. Beans and pulses are often added to the diet as good sources of protein that are low in fat. Because of their low glycemic index, adding beans and pulses to the diet may also have other health benefits.
|Food (150 g cooked)||Glycemic Index|
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The University of Sydney