So what about soy? Is is good or bad or what? I think you should generally tend to try to avoid soy (except for perhaps tofu). Soy is not really a nutritional "food". It has been genetically engineered in the United States to grow where other plants may not grow, and it is genetically engineered to be resistant to Round-Up (yes- that's the herbicide chemical that kills weeds).
My major problem with soy is that it is in just about everything! It is way harder to avoid than even high-fructose corn syrup. Take a look at any ingredient label in your kitchen right now- do you see any of the following ingredients? Hydrolyzed vegetable protein, vegetable protein concentrate, vegetable oil, MSG (monosodium glutamate), soy protein isolate, soy lecithin, textured vegetable proteins and, the most prominent of all, soy oil. Try to find something in a package that does not contain one of these ingredients- you will have a hard time.
Some of the possible side effects of consuming soy are: estrogen effect in men, women and children due to phytoestrogens, blocking the absorption of calcium, digestive problems and upset stomach, impairs thyroid function, increases the body's need for Vitamin D and B12, weight gain, and possible cancer links.
Soy is popular because soy is cheap. It provides cheap feed for animals- and contributes to the same effects in animals as in humans. The American Soybean Association is a powerful political lobby in Washington. The number one producer of soybean seed in the U.S. is Monsanto- the same company that makes Round-Up. Pretty convenient, huh? You can find more about soy in Kaayla Daniel's book
The Whole Soy Story: The Dark Side of America's Favorite Health Food. Google "dangers of soy" if you want to read more.