I don't think soy is the extremely dangerous food its detractors make it out to be (at least in its unprocessed forms) but I don't think it's a wonder food either. Awhile back it seemed like soy was being added to lots of processed food products as yet another hyped-up nutritional bandwagon rolled through town. I really like tofu, but my family doesn't, so I don't eat it very often anymore.
I found this thread in Jeff's forum a few years back to be very useful:viewtopic.php?t=5600
Here's an excerpt:
Tofu/Soy first became popular based on the myth that vegetarians had to be careful about protein. Now, soy is popular because it is promoted as a rich source of phytochemicals and other nutrients. This may be true, but so are most other beans and other plant foods, so we have to look at the total package.
Soy if high in fat and higher in calorie density than any other bean other than the peanut (which is also technically a bean). So, while not as high in fat or calorie density as peanuts, I would still consider soy a rich food, which should be limited and thought of more as a condiment.
And, by the way, that is actually how it is used in China and Japan. One study that looked at the differences between low and high soy consumption in Japan found that in the high soy consumption group, they were consuming around 58 grams a day of soy, equating to about 7-9 grams of soy protein per day. 58 grams iis around 2 oz. The amounts in China are not much different.