Japanese researches determined that 30g of soy isoflavones per day have been linked with thyroid dysfunction, but the study was poorly designed.
Facts and fallacies about soy: (ignore the BS spread on "anti-soy" campaign sites)
nutra-smart.net/soy.htm
Personally, I avoid the stuff.
I'm getting most of my protein from whey - see the "Whey protein concentrate orders" thread in the supplements section.
See Table 1 :
www.vrg.org/nutrition/protein.htm
