Is there any reason to think that "separately" is the preferred way? As for not knowing the components of a healthy diet, that objection applies equally to taking in food the normal way, so I really don't see the relevance. If we don't know enough to build a proper slurry that contains everything, then we don't know enough to build a proper normal diet that contains everything.
One other aspect I ignored in my earlier post is that the digestive tract actually needs solid mass in order to perform peristalsis. Hospitals have to avoid giving patients a liquid diet for too long, or else the digestive tract basically just stops — and it's a pain in the ass to restart.
Additionally, we have only the faintest idea how this might affect gut bacteria, which is an enormous component of both our digestive system as well as immune system. Without giving them our "table scraps", what happens to them?
