Rob once wrote an article with a section discussing GMO foods. You can find it here: http://robrhinehart.com/?p=572 Here is an excerpt:
Genetically modified foods are of course heavily regulated by the USDA and FDA and are completely safe. In fact, controlling the evolution of a food is likely much safer than trusting it to evolve on its own, which could produce any number of toxins or allergens.
If Rob is actually still in charge of the whole Soylent thing, I would not get my hopes up on ever seeing a version of Soylent without GMOs. (Also, notice in that article, it mentions that many GMOs actually improve the nutritional value of the food. So, using GMOs may actually be increasing the quality of Soylent.)
Also, serious research aside, do you know how much soy the typical Japanese person consumes? If soy products had enough estrogen mimicking substances to cause “feminization,” we would have strong scientific proof of it (there would be no room for controversy). Phytoestrogens are called that because of chemical similarities to estrogen, not because they mimic the hormone in the human body (in fact, according to the first paragraph on the subject on Wikipedia, many phytoestrogens bind to estrogen receptors, blocking estrogen and causing antiestrogenic effects). There is some evidence that some phytoestrogens can weakly mimic estrogen, but so far there is no evidence that this has any significant impact on humans (though, there may be a reason for concern in male infants, who may be more susceptible ). Also, might I suggest looking at the Wikipedia page on this subject, under the subheading “Males.” It cites three sources discussing research that has shown that phytoestrogens have no feminizing effects on male humans. (There is no conclusive research on females. Some studies have shown an effect protecting against breast cancer, but some in vitro studies show that there might be an extremely small risk of causing cancer, at least in the presence of other chemicals commonly used in in vitro studies. Note that none of these studies have tested with the very small amounts normally consumed by humans, even in Soylent, and Japanese people, who consume far more soy than nearly anyone else, have a much lower cancer rate than Americans.)
As far as bioavailable nutrients go, I am with you on that one.
Note that for many people, price is a major factor. Perhaps the highest value application of Soylent is in providing decent nutrition to the poor. Few poor people can afford healthy food, even on food stamps (in a large degree because the government makes poor people spend absurd amounts of time jumping through hoops to keep their welfare benefits). If you have several hours a day to prepare food from scratch, it is possible to get food costs down to $1.00 a person per meal, and less in some areas. Some people can afford to pay extra for prepared foods, but Soylent is not designed to be a great tasting prepared food alternative. It is supposed to be a cheap food replaces that reduces labor and cost. Soylent is not designed to be a luxury food, and it is certainly not designed to avoid all of the substances that are common targets of scare tactics. It is nice to see the reduction in sucralose, though there is no evidence that it is harmful to most people. Note that the point was not to reduce something that is potentially harmful, but rather to alter the flavor. Without real evidence that GMOs are harmful though, I do not expect the recipe to be changed just because a few people are afraid of them. Likewise with the phytoestrogens. As some people mentioned earlier in this thread, the composition of Soylent is based on science and research. If the recipe was altered every time someone wanted a change that is based on fear or personal preference instead of scientific evidence, it would quickly become very unhealthy and extremely expensive.