It has almost no effect on your blood glucose level. This is something that is very important to anyone with diabetes and to many other people as well. Technically, it has one of the lowest indexes of any food on the glycemic index, 8 (where glucose = 100). Its index is 5 according to one study and 11 according to another.
This bean looks just like yellow split peas, but is quite different because it doesn't readily boil down to mush. It's more closely related to garbanzo beans, or chickpeas. The differences are that chana dal is younger, smaller, split, sweeter, and has a much lower glycemic index.
For more details, go to below link. A foreigner has adopted chana dal/besan as his main food to tackle diabetes.