There has been a bit of a soylent fad in my friend group recently. I'm interested in it as an occasional replacement meal. I have noticed that I'm a little more energetic when I do, suggesting I need to change my diet...

Still, there are some people who have taken the fad to close to extremes, and seem to be doing okay. There are plenty of "One Month Soylent Challenge" or longer blog posts that I've seen in passing, praising and condemning its merits. I know the liquid diet isn't a new thing, but some people claim that just merely by it being liquid has a detrimental effect, others claim that there's no way some miracle food can work.

I like variety, but I was wondering if anyone here had more down to earth criticisms. A lot of the anti-soylent things I've seen were mere opinion.

  • One of the claims I've heard is that with a varied diet you will naturally correct imbalances by craving food that is rich in whatever you have a shortage of, whereas if you're eating one thing all the time and it's not the right mix for you there's no way to correct. I don't have any citation though so not posting this as an answer.
    – Random832
    Jun 3, 2015 at 20:53
  • In the DIY community, that's less of an issue for the creators, as they are very much in control of the recipe. For me, that also isn't an issue, as I generally get at least one real meal a day, or more. That is a decent start to a counter point if it can get backed up. Everyone is different, so there's no miracle food, but it's still probably healthier than a lot of the diets of people who live near me...
    – Poik
    Jun 4, 2015 at 3:25
  • 1
    I question some of assumptions that Soylent is predicated on. One is that we know exactly what the human body needs and can just put it in a shake. But what if there are micronutrients in real food that we just haven't discovered yet? Or what if the nutrient in the shake simply doesn't work when distilled into pure form, without the natural packaging provided by, say, the apple it came from. We evolved to eat food, and assuming that we can eat a processed version may be misguided. Jun 8, 2015 at 18:12
  • wow, I did not see that! lol thanks... and deleted
    – nelomad
    Jun 20, 2016 at 20:32

2 Answers 2


I think the biggest issue (already mentioned by Joshua Frank) is our flawed understanding of how nutrition interacts with human health, especially for the long term. If nutrition were as easy as Soylent claims, well, we could take a multivitamin and eat ice cream for the rest of our lives, no problem. But what do you know, it's more complicated than that. We're constantly discovering new nutrients or new roles for nutrients we already knew about. We now know from microbiome- and psychology- related research that we are not simply the sum of what we eat, but also why we eat and how we eat.

You probably won't die from consuming Soylent (people eat more terrible things all the time), but I wouldn't consider it any healthier than, say, Wonderbread with a multivitamin chaser. In the end, I merely consider it another addition to our supermarkets full of highly processed food.

And dude - it's made of people. Gross.

  • 1
    Welcome to Health! This post has the makings of a very good answer, but here on Health, we strongly encourage using references. They are the only way in which we can tell if information is reliable or not. If you are struggling to find good sources, check out, What are reliable sources? If you want to learn more about our site's stance on answers without references, check out, Should answers without references be immediately deleted? Thanks :)
    – michaelpri
    Jun 20, 2015 at 4:15
  • I love the Soylent Green comment. And I agree with the points, but I think the fact that no one has given a single reference for this question at all so far just show how little we can say on the subject at this time. I'll leave this up, since the liquid fad will make a resurgence even if Soylent dies. Also, @michaelpri, I don't know if that should be enforced unless someone can fully answer the question at all. (So I agree with Susan here.) Otherwise, yes.
    – Poik
    Jun 20, 2015 at 20:37

The wisest thing ever said on television was in an old margarine commercial: "It's not nice to fool Mother Nature."

Eating Soylent exclusively, or as a high percentage of food intake, is unwise, and the fact that some people seem to be getting away with it, unscathed, should offer little reassurance. As others have remarked, we have no way of knowing if we know all the essential nutrients Mother Nature wants us to have. And we may not ever know, because nutrient deficiencies can take years or decades to appear. Vitamin B12 and vitamin E are examples of this.

I recall one lecturer talk about a vitamin or mineral deficiency that was discovered by medical science only because a woman had habitually eaten nothing but an egg on toast for 20 years (cannot remember what it was). And then there are other deficiencies that have come to light much more recently, when hyperalimentation solutions lacked something that humans had never before suspected was essential (I'm thinking vanadium, but again am not sure).

On top of this, I would additionally be concerned about the very naive medical reasoning that Soylent's inventor evinces. On this page http://robrhinehart.com/?p=424 he wonders if his family's fondness for tomatoes reflects a salutary effect of lycopene peculiar to his family's genetics. Nothing is impossible, of course, but the unstated assumption, which appears often in Soylent discussions, is that human appetite for specific substances is correlated with the body's need for, or benefit from, those specific substances. Although true for calories (we get hungry when deprived of calories), in general it is balderdash -- go read about pica and cissa. (You'll read, for example, about iron deficiency causing a massive craving for ice, which is, of course, iron-free. Iron deficiency also causes craving for tomato seeds, which are poor in iron; maybe the inventor's family is iron deficient.) And then you can go read about B12 deficiency (called pernicious anemia, because it was uniformly fatal). Those people had aversions to meat, when, in fact, meat was the food richest in the nutrient they were missing.

Life is an exceedingly complex and subtle machine, and it's risky to think that humans can re-engineer macro processes that are built into us at the deepest levels. If you consume a lot of Soylent and get a disease unknown to medical science, I will be very happy, because we will have learned something about metabolism, and minimally sad, because it was a choice you didn't have to make.

  • Before flaming me for omitting references, be aware that I have a different philosophy about this website. I want you to go off and do your own reading. I can cite references to prove exactly opposite propositions for anything in medicine. (Tobacco companies perfected this art.) Don't trust me, or anyone else except your doctor. Jun 20, 2015 at 23:50
  • Eh. If I contribute to science, then my life was worth it (but I don't eat a lot of Soylent and my recipe changes with cravings). I agree with your opinion on references too. However, links to the cravings and the egg on toast story would be cool. Also, supposedly it's not ice, it's crunchiness, which in the old (as in almost pre-fire days) meant bone, which meant marrow which is full of iron.
    – Poik
    Jun 21, 2015 at 15:03
  • Nice point about the crunchiness, and maybe it is true, but even if it were, the misdirection to ice highlights the pitfalls of a 21st-century human trying to interpret cues that evolved on the African savannah a million years ago. BTW, geophagia (eating dirt) is also quite common in iron deficiency, and it is not very crunchy! Jun 21, 2015 at 22:27

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