The magic ingredient is SV tech culture. You need the placebo effect of a food product with release notes (https://www.soylent.com/notes/).
What products would those be? Most meal replacement shakes marketed in the US are for people trying to lose weight, so they have far less calories and fat than a meal for people just trying to eat healthy.
Have you heard of Ensure?
Yeah, I even wrote a paragraph bashing it (or at least, people claiming that it's a product of serious medical research) last time we had a Soylent thread. It has a lot more sugar and carbs than most people would want to eat regularly, which makes it more suitable as a temporary food replacement or a snack than a lunch staple.
Try something like Glucerna. It's like Ensure but for diabetics, so it has a lot less sugar and carbs.
Jevity?
Yeah, stuff like Jevity is probably worth a look, but you'll have to excuse people for never considering it seeing as Abbott never thought of marketing it to overworked nerds.