I have always read and been told that soy protein inhibits testosterone production to a degree-I have always stayed away from the stuff(soy)-I think i read that about 10 years ago...I like whey,egg whites and whole eggs, and lots and lots of good ole USDA BEEF, BEEF, and more BEEF.1.5 pounds sirloin per day(and a half gallon of Breyers Vanilla Bean ice cream EOD....