My lab has done a lot of research and compared soy to wheat, eggs, and whey. With 16% protein diets, soy does not significantly increase protein synthesis postprandially; neither does wheat. Whereas Whey and Egg do. Two mechanisms are higher leucine contents of whey and egg. But also, we showed that soy increases AMPK; which inhibits the mTOR pathway and protein synthesis.
Chronically our soy rats are significantly smaller than the rats on our other diets. They have about the same fat mass as whey and egg; but a lot less muscle.
From other labs I have seen studies show that it may decrease testosterone.
Benefit is that AMPK does promote leanness and enhance insulin sensitivity.
But you can increase AMPK with other methods - principally exercise. And without the other side effects.
Gabriel "Venom" Wilson, Ph.D. Nutritional Sciences
B.S. (Hons) & M.S. in Kinesiology, CSCS
Vice President, ABCbodybuilding
Co-Editor. of JHR
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