We have no idea what all the important components of a balanced diet are on a chemical level, it is incredibly naive to think that soylent can mix up a cocktail that would be optimal.
Also, what does "optimal" even mean? You're setting the bar too high; as long as they're healthier than typical alternatives of eating lots of fast food and processed packaged foods then their addressable market is huge.
this is exactly the kind of research soylent doesnt have on their products. we have no idea if they are 'healthier' or not.
Soylent set the bar that high during their kickstarter by saying it would put you in perfect health, and was suitable for everyone.
You call that food? Suddenly the 'balanced diet' everyone seems to be pushing is not applicable? Yeah ok, I agree that if you are coming from a mcdonalds-only diet, you might do better, but they are positioning themselves as a healthy meal replacement.
I know that's not a scientific study by any means, and people should be skeptical, but there really is a lot of (anecdotal) evidence out there of Soylent having a positive impact on people's diets. On the other hand, I've hardly seen any evidence of Soylent having a negative impact on someone's health.