[tcoppi]

I don't have a source off hand but I remember the heart-healthy effects of soy being quite small in magnitude. Personally I try to avoid anything that has the potential to be a strong endocrine or hormone disruptor like soy and plastic products. That is nearly impossible these days, but it makes me feel better :)

[marricks]

It may be small, but if you read the source far more documented and larger than any potential "hormone effect" of soy. Also larger practical effect on your life.

[tcoppi]

There's plenty of evidence in the links I posted for a large effect of high concentrations of circulating soy compounds in the body. I don't doubt that it is a non-issue for most people consuming normal amounts of soy. The issues I have, and they are not well studied, is 1) what do concentrations look like over long periods of normal-to-higher consumption of soy products(like long-term usage of Soylent, nearly 100% soy protein) 2) is there an additive or synergistic effect with other, stronger hormone and endocrine disrupting compounds like those found in some plastics and plasticizers, your exposure to which is effectively impossible to eliminate in modern life. Neither of those two are well studied, and I'd personally like to try and reduce my exposure to either situation.

Most people don't care, and that's fine, but there is evidence it could be a problem.

Edit: I'll also add that to be fair to Soylent, they use Soy Protein Isolate, which has drastically reduced levels of soy isoflavones compared to straight soy protein. That alone probably reduces any potential harm to near-zero, but I personally like to reduce my exposure as much as possible, so as long as there are alternatives that are equal or better(as there are with soy) I will reduce my exposure. YPRCMV(your personal risk calculation may vary).