Are ensure et al nutritionally complete? As in - you can live off ensure and nothing else?
My understanding is that soylent (and clones) are able to be full replacements for food in general, whereas ensure, muscle milk, etc, are meant to be purely supplemental
When Ensure markets itself to the general public the makers responsibly say it's a supplement. But if you're a medical professional you get the other marketing - which is clear that ensure etc can be used as a sole source of nutrition under medical supervision. They have a variety of products to cover a variet of needs. They have ensure plus which has more calories than ensure; they have products for NG tubes; they have low protien versions; there are version for children; etc.
The fact that they limit this marketing to registered healthcare professionals and have a bunch of caveats about "under medical supervision", and Soylent doesn't, is something you can draw your own conclusions about.
Some people will see this as disruptive and an example of a small nimble supplier filling a niche; other people will see it as SV pathologically avoiding reasonable regulation.
Given the number of people under close medical supervision who are using Ensure for meal replacement, why hasn't vitamin poisoning from Ensure been observed or reported?
The others are designed to do that, but the jury is still out on if any specific product and completely replace food with one shake/formula. Be it Ensure, or Soylent.
My understanding is that soylent (and clones) are able to be full replacements for food in general, whereas ensure, muscle milk, etc, are meant to be purely supplemental