I was looking into ensure after a few people mentioned it on this thread. Something ensure promotes is that it's good for in between meals but doesn't say outright that it is an entire meal replacement that I could see. I think the difference is Soylent is meant to be a complete diet replacement where Ensure is focused on being a supplement to your diet.

All the meal replacement shakes explicitly state that they are NOT full replacements but only as a part of a balanced diet.

What I'm wondering is if that means that they are not trying to include 100% all nutrients, or is it just a legal claim to pretect them, since noone knows 100% all necessary nutrients.