I have PCOS, which is just one step further than Syndrome X, and the same, if you ask others. My endocrinologist told me either low carb or low glycemic would be good for me. Your diet may be different depending on how high your insulin resistance is.
Atkins and Protein Power would be low carb, which would have no grains, and Sugar Busters and South Beach would be low glycemic, which would have good carbs like whole wheat bread and brown rice and dried beans, but nothing refined like white bread-potatoes-flour, or sugar. Check out the PCOS forum. Anything on insulin resistance (IR) might be of help to you.
http://www.3fatchicks.com/forum/forumdisplay.php?f=70