[Retric]

Jevity one of the abbot brands you mention is clearly designed for long term use as 'sole-source nutrition'. And, I am sure someone has lived off of Ensure, but just because they also sell total nutrition products does not mean Ensure was designed for that role.

Design goals matter, Jevity/Oxepa/etc being designed for feeding tube use has little focus on taste.

Another example, Osmolite is sole-source nutrition but it's low-residue which is not good for healthy people who need more fiber.

PS: You can look through there brands, but there is a reason they sell so many different kinds as they each have different trade offs.

ED: I have had significant digestive issues in the past so I have done some research into this. And, talk to a nutritionist before going on any unusual diet, it's easy to mess things up long term.