After reading Dr. Mercola and Nina Planck, I do not eat most soy products or give soy to my family anymore. If it is protein you want, what about just beans?
I have come to the conclusion that soy is really, really bad for us. It's, as Planck calls it, a completely industrial food. It throws hormones out of whack. And, it lurks in most processed foods!
Some places suggest that fermented soybeans are OK (natto, soy sauce, tofu). We bailed on tofu, soy milk, and other products containing soy flour or oil.
Go to mercola.com and search for soy and read for yourself! I felt pretty horrified after I went through all of the articles.