It is just as @deadrat said in the comment above. Ground up does indeed mean from the beginning, but ground-up means ground, as in hamburger.
Soylent is a food replacement drink named after the movie "Soylent Green", in which people unknowingly ate processed humans.
They are kind of ghoulish about it themselves, though it is (presumably) a soy-based food replacement.
Soy food-replacement named Soylent? "Ground-up" is in quotes to underscore it's "roots", a play on words reflecting a particularly telling scene in Soylent Green.
Venture-backed food replacement drink maker Soylent – yes, named after the movie where people unknowingly were sustained by eating other people – is out today with its newest product. The company this morning introduced “Soylent 2.0” (still not people), which is actually a vegan, soy-based nutritional drink that’s now shipping in a ready-to-drink package.
Soylent 2.0's promo photo even has a question mark on the bottom of a mysteriously blank white plastic bottle.