Patch said:
pianoman - if you can point me in the direction of those studies I'd be very grateful.
Of course, here they are :
The latest was in the Atkins Diabetes Revolution by Vernon, Eberstein. They say that if a person has been following a low carb diet, prior to an GTT they should eat 150 grams of carbs a day for at least 4 days to get an accurate test. They also recommend measuring insulin along with the test.
An older paper by Joseph Kraft, 1975, says higher carb for two weeks, but doesn't state a level :
http://mvl.meridianvalleylab.com/wp-content/uploads/2010/06/DrKraftInsulinGlucoseArticle.pdf
The relevant discussions starts on the bottom of pages numbered 16 and 18 (but physically pages 5 and 7 in this PDF)
And the study including Vilhjalmur Stefansson and his colleague Karsten Anderson (VS and KA in this paper) was even earlier from 1929... when apparently even the "establishment" were open to the idea of low carb diets -- before fat was declared public enemy No. 1
http://www.jbc.org/content/83/3/747.full.pdf
If you want to read more of Stefansson's "Adventures in Diet" which he published in 1935, it is on-line here:
http://www.biblelife.org/stefansson1.htm (not a religious article)