>what advantage they'll be able to offer over established meal replacement drinks like Ensure
Ensure isn't remotely close to nutritionally complete. We're not talking about your mythical unknown magic plant powers here, we're talking known vitamins and essential minerals, with established RDIs, that Ensure and similar products do not come anywhere close to providing enough of. If you can show me a product that is actually nutritionally complete (provides 100% of the RDI of all vitamins and minerals with an RDI) then you have an argument.
Ensure isn't remotely close to nutritionally complete. We're not talking about your mythical unknown magic plant powers here, we're talking known vitamins and essential minerals, with established RDIs, that Ensure and similar products do not come anywhere close to providing enough of. If you can show me a product that is actually nutritionally complete (provides 100% of the RDI of all vitamins and minerals with an RDI) then you have an argument.