Unfortunately reality is much more complicated, and this is why nutrition science is an extremely hard and fuzzy field (and in my opinion, generally sketchy).

Unfortunately reality is much more complicated, and this is why nutrition science is an extremely hard and fuzzy field (and in my opinion, generally sketchy). The problem is that nutrition, at least at this stage, is simply not analyzable, unless we're talking about very large effects - as somebody in a post has explained. Supposed that, say, soylent, kills people in 30 years of consumption. What's going to happen in the meanwhile? Or, worse, suppose instead that the effect is subtle, for example, that it causes debilitation in the long term. How's that going to come out? Sadly, some nutritionist will make 50.6 people run for 25.3 minutes on a treadmill, then come up with the conclusion that there is no significant negative effect, which is going to be trumpeted on mainstream publications. Let's talk about iron. One problem with vegetarians is that some fall very ill if the don't eat meat, even if they take iron injections. How nutritions science explains that? Unfortunately, it can't. (actually, this is a serious doubt in vegetarian circles. There is the suspect that some big vegetarian advocates are secretly eating meat because of this or similar problems). The big problem is that products like soylent carry the underlying message that science has a clear idea of how the human body works, while in reality, it doesn't, and this is a very, very serious problem.