Whilst doing some research to get my head around GI and GL (having swapped arborio rice for pearl barley in a risotto and got a good result with my bsl) decided to google pearl barley and after a few links came across this. I found this webpage which lists the GL of a lot of basic foods. It is very user friendly and helpful. mendosa.com/GI_GL_Carb_data.xls#'All foods'!A968. :mrgreen:
David Mendosa is a diabetic and a well known writer on the subject, although he has no medical qualifications. His work is highly respected in the US and he is a regular contributor of articles to the American Diabetes Association, the New York Times, etc.
You might also be interested in this link which is to a similar GI list produced by BUPA so contains more UK foods and brands than on the Mendosa shreadsheet.