The incorrectness of Soylent
Soylent is a liquid meal replacement born in California a few years ago. For people too busy to eat or too busy to prepare meals, it offers great convenience. You can live on Soylent.
It is a cleverly-made product that embodies answers to most criticisms that might be made of it. It is for instance made from grains and other vegetable products so is acceptable to vegans. Yet there has been great opposition to it. Before I look at why, I should perhaps declare that I have an interest of sorts.
In 1967 when I was in the 4th year of my psychology degree, our professor of physiology mentioned to the class that skim milk has a very similar nutritional profile to the liquid diet that American astronauts at the time were being fed. Just add a few vitamins and you should be able to live permanently on nothing but skim milk. Being both busy and having little money at that time, the idea appealed to me. So for six months I lived on skim milk plus some supplements. I was fine. The diet worked. No problems. I gave it up only because of boredom. So I have the experience to find the Soylent story reasonable.
So what have people got against Soylent? Just Google 'Soylent' and you will come across a whole lot of grouchy comments on it. I have read a lot of those comments. The most scathing seem to come from people who have their own barrow to push -- from GMO opponents to sugar-opponents. Soylent obviously does not bow down sufficiently to their particular obsession. From my reading of the medical journals, I consider opposition to GMOs and opposition to sugar as ill-informed so I regard all that they say in their attacks on Soylent as unreliable and not worth pursuing.
The majority of the negative comments however just seem to come from the break with normal human food practice: It's unnatural; it deprives us of pleasures; and disrupts social interaction. And some of course didn't like the taste, texture etc. Though the critics who actually made an attempt to live on Soylent for a little while were generally rather surprised by its palatability.
And like all new products it had teething problems, with early formulations triggering food insensitivities in some people. Those problems were met with slight reformulations of the product and it should not now give those problems.
So, basically, it seems to me, the opposition to Soylent is mainly a combination of snobbery and a fear of the new. As an alternative to a normal diet it would seem to have few problems. Living on it would probably reduce your social interactions and it will never taste as good as a well-cooked T-bone but nobody claims otherwise.
The only real scientific objection to it that I can see concerns the bioavailabilty of its ingredients. Its micronutrient profile fits well with official guidelines but there are various ways of meeting those guidelines and some ingredients may have greater bioavailability than others. Some further research on that may be worthwhile. The product would however seem in general to do well what it purports to do.