Soy milk has long been a favorite substitute for those who can’t tolerate milk. Since milk holds an uncertain place on the Paleo menu, does that mean we can include soy milk?
A Whole Foods Diet
Not even remotely. Living a Paleo lifestyle is all about eating whole, natural foods, and soy milk is anything but those things. It’s made by soaking, grinding, boiling, and straining soybeans, a much more involved process than simply squeezing a cow’s udder.
The Problems with Soy
Soy milk also contains all the anti-nutrients of soy, including phytic acid, which interferes with mineral receptors in the body, leading to mineral deficiencies.
Mark Sisson has a pretty comprehensive post on soy here.