I think that many of us have been advised at some point by our medics to go high carb, low fat and low sodium, either to "control" diabetes and its "side" effects, or to help with hypertension.
My revelation came when I first got hold of Dr Bernsteins book "Diabetes Solution". He lays out a true diabetic road map and covers many of the lesser know issues relating to diabetes, for example the "dawn effect", gastroparesis (sp?) and so many other issues.
He is a true low carb proponent and I have given his book to many friends. It is essential reading for all diabetics. His web site is here but is no substitute to having his book and reading cover to cover. The man is a genius.
http://www.diabetes-normalsugars.com/index.shtml