The Science Questions Thread


My apologies if any/all of these questions have been asked before.

Okay, it’s time for the hard-core science. Below are a large number of highly technical questions, and my hope is that the community as a whole will be able to answer most of them, while the producers of Soylent can answer the rest.

Here we go:

  1. Multi-vitamins have over 9000!! of all the required compounds. But often they are not absorbed by the body properly, and end up just being excreted. Ie, it’s not enough to put the Daily Recommend Intake of substance x in a thing.
    a) Has Soylent been formulated to ensure maximum absorption efficiency, and
    b) is there a recommended rate of consumption–I’ve heard don’t chug it, but should it intake be x amount of Soylent over y time to achieve optimal absorption?

  2. regarding complementary/competing nutrients-- some compounds promote/inhibit the absorption of other nutrients. For example, I believe there’s a protein in peanuts that makes milk more nutritious. Others are perfectly fine as complementary nutrients, but in the presence of a THIRD, more preferable nutrient, the original nutrient will remain unabsorbed.
    a) Has Soylent been formulated with these interactions in mind?
    b) I assume that no one food/drink will be perfect with regards to this issue. Does Soylent produce a deficiency of x as a result of competing or preferential nutrient interactions over any period of time?

  3. re: complete vitamins compounds. Slightly related to 2), and as an example, ascorbic acid is marketed as vitamin C. But there is a better form of Vitamin C that comes as part of a larger molecule with a very important bioflavonoid that breaks down readily, and therefore is omitted from most mass-marketed products, to the detriment of the consumer.
    a) Which, if any, of the nutrients included in the Soylent nutrient profile are “unpaired” from their native compounds?
    b) what deficiencies, if any, do these unpairings produce?

  4. Is Soylent intended as a meal replacement or as a nutritional supplement? I know many consumers are consuming Soylent and nothing else, and seem to be doing okay. But what is the intended use, and what is the reasoning behind that decision to be one or the other?

  5. Re: microbial profile of your GI Tract. As an example, we consume “resistant starch” that directly feed the beneficial microflora that make up the bacterial segment of our immune system.
    a) Does Soylent contain “resistant starch” and, if not, to what degree does the adaptation of your GI microbial profile compromise your system’s immunoresponse, either by reducing its ability to respond to pathogens or by altering its profile to allow opportunistic, harmful bacteria to establish a foothold or even overtake the GI environment?

  6. Related to 5), and regarding the “adaptation” of our GI tract to better absorb/metabolize Soylent, and by adaptation:
    a) What is the generally accepted consensus range of time (given that it’s dynamic based on the individual) required for the microbial life in the GI tract to adapt to optimally react with Soylent?


I’ll answer #4. It is designed to be a full diet replacement. It can be (and is) used as a meal replacement for one or two meals. I don’t think it would work as a nutritional supplement, as it contains calories alongside the vitamins and minerals. A serving of Soylent is a meal and should be treated as such.


bump. Really do want these questions answered. As we get more established, they’re inevitably going to be asked by the scientific community, so in all honesty, we’d better have our answers prepared by then or we suffer an unnecessary PR setback when the reductionist, sensationalist media soundbyte is that Soylent doesn’t stand up to scientific scrutiny.


There’s also the question of legal framework–in very general terms, the FDA regulates most everything that is intended for use inside the human body. N.B!!! I am not a lawyer, and any of this particular reply is subject to correction by anyone who knows better.

I know nothing about Soylent’s current status according to the FDA. I can’t imagine how it could have become an approved substance when its intended use is an exclusive nutritional source. To my knowledge, the FDA literally cannot approve something that doesn’t have clinical trials that clearly demonstrate that 1) it’s working as intended and 2) it doesn’t create unreasonable/unmanageable adverse effects.

Of course I’m aware that no clinical trials exist for Soylent; but I’m also aware that, if no one ever starts using it outside the system, there never WILL be clinical trials.


Soylent is food, made with ingredients generally recognized as safe (GRAS)–like any other packaged food you buy. A loaf of bread. Kraft Mac & Cheese. A frozen breakfast burrito. A bottle of iced tea. A box of Cracker Jacks.

The ingredients are regulated; each individual recipe doesn’t have to be.

IANAL either.


Some of these questions I imagine an ambitious enough person could answer through internet research (though it would be quite a bit to research how each ingredient interacts with each other ingredient). for others, I wonder if we might be pushing against the limit of our current understanding of nutrition science. Number 5 I imagine would require its own experiment (or set of them).


Well, I’m kind of sad that the questions didn’t get answered—I’m gonna chalk it up to the answers aren’t out there. Which isn’t an indictment of Soylent as much as it is one of our current knowledge on nutrition in general.

I guess there are just too many variables to track; whole nutrients vs individual ingredients goes beyond our current knowledge. At which point, I think I’m going to have to put a hold on my Soylent ambitions. I KNOW food works (I try to abide by a paleo-style diet). It’s a pain the ass. But it’s got roughly 50,000 years of anecdotal evidence in support of it. Soylent is just too new, and nutrition too…foundational for me to want to make a guinea pig out of myself–especially given how I would be doing so without even the comfort of at least knowing that the results of my contributions will be included in a scientific study. All we’re doing at this point, it seems, is creating a whole bunch of anecdotal evidence. And it’s gonna take a while before we get to parity with that whole evolution thing.


Yeah, food works for me too. That’s why I eat food. Right now I’m eating soylent for food.


I think you are doing something that many others do, namely holding Soylent to a different standard than ordinary food. I honestly don’t know whether Soylent has been designed for maximum absorption of this and that as you ask, but one thing I do know is the ordinary food people eat is NOT designed for those same things. People seem to ask all kinds of critical questions about Soylent that they don’t ask of ordinary food.

Every fruit and vegetable anyone eats contains pesticides no matter how it is grown because pesticides are an inherent part of fruits and vegetables because rather than fruits and vegetables being designed to be optimal for humans, they instead are things living out their existence and one way to do that is to evolve physical defenses against pests, which is what pesticides are. Whether or not those physical defenses harm humans in the long run are irrelevant to the interests of the fruits and vegetables.

That’s not to say that fruits and vegetables are bad for humans to eat. As far as we know right now fruits and vegetables are generally good for humans to eat. But they aren’t optimal for humans nor does it make sense to assume they are.

None of the foods we eat are designed to be optimal for humans. We’re here on a planet and we have to eat to live so we eat whatever we can to survive. Sometimes the relationship is symbiotic. For example, 50,000 years ago we’d eat something and it would give us enough nutrition to keep us going and we’d drop the seed for it somewhere else and that would help it grow anew. So the plant is helping us to survive and we’re helping the plant to spread. Fine. But that does not mean that us eating the plant is the best way for us to survive nor does it mean that us dropping the seed elsewhere is the best way for plant to spread.

As far as what we’ve eaten the past 50,000 years, it has varied a lot over time and place. There is no single human diet over the past 50,000 years, rather there many of them. And none of them were designed to be optimal for humans. Yes, they’re all good enough to keep us going for years on end but so are lots of other diets that people would recoil at.

Nutrition is complex and there is a lot we don’t know. So let’s keep learning. But the notion of trying to figure out exactly what it is that we physically require and foregoing great taste for it in exchange for convenience and lower cost while simultaneously optimizing health (or always striving towards that at least) seems like a pretty good idea to me. How well it can be accomplished given our current knowledge and technology is a separate question.


You make some really good points, yngh. I’d like to say that I try to avoid ordinary food. Which is to say, I stay away from what I presume you’re referring to: the Standard American Diet.

There’s so much crap in the SAD even ignoring fast food that it’s not even funny. That being said, the laws that govern what can be labelled “organic” are much more strict in Canada (where I live) than they are in the USA, so hopefully, I’m only dealing with the “natural” pesticides you referred to in things like fruits.

To that point—fruits aren’t looking to be eaten by insects, and so yeah, they probably have compounds that are harmful in one degree or another to them. They ARE, however, meant to be eaten by larger animals, like birds, bears, humans etc. That’s how they reproduce. Their seeds pass through our digestive tract and are deposited back into the landscape in a middle of a fertilizer pile. Very advantageous for the fruit’s propogation. Wheat, on the other hand, is meant to be wind-blown, and therefore contains some toxins of the type you mentioned, and unfortunately, the wheat we eat today is WAY higher in gluten content than it was even a hundred years ago, hence the rise in ciliac and similar diseases (among many other factors). Those toxins may have relatively innocuous effects on their own, but they can have serious effects on the microbial profile of our intestinal tract, which dictates how we absorb/metabolize what we do, ie, that’s HUGE. It can also have an effect if it is a persistent toxin.

But all of this boils down to a discussion about evolution. It’s not so much whether or not this or that food was intended to be eaten by this or that creature. It’s about how well both food and feeder concurrently, and yes, sometimes, symbiotically, adapt to take advantage of that relationship. The creatures whose biochemistry/physiology provided the greatest net advantage when doing such and such an activity were statistically more likely to reproduce. The creature that had this or that defense against such and such a threat (disease, poison, etc) would be most likely to survive the onslaught and so would pass on the genes that provided that defense.

It’s why MRSA exists. The 5% of “resistant” bacteria that survived the 95% die-off of that culture’s population as it was being treated by antibiotics became 100% of the population that moved forward.

So the question is, how well did we adapt to eat the food we hunted and/or gathered? We don’t actually know, but we can make a pretty strong inference based on the abundance of anecdotal evidence: “really, really well”.

It is THAT body of “food” that I refer to when I say we have 50,000 years of anecdotal evidence that says we’re good at deriving what we need, nutritionally speaking, from it. Not the SAD which is relatively new to the scene, say, around a century or so.

With regards to holding Soylent to a higher standard–I don’t think I am–at least, not so badly that it’s a problem. We’re talking about a whole dietary shift that treats our nutrition as a series of isolated ingredients mixed together, as opposed to a bunch of whole (macro)nutrients that show up in our digestive tract together, and that we’ve adapted to process concurrently, such that, if one of those macromolecules is missing, the other goes unabsorbed (or sub-ideally absorbed). This is not an experiment with insignificant implications. You bet your ass the standards ought to be pretty high.

I’m not saying it can’t work, but I’m saying that I’d like to see some studies that show that it does (in the interests of not having to wait 50,000 years to get on par with our historic diet). What are the side-effects of this diet from generation to generation?

It’s a fact that the nutrition being absorbed by both the mother and the father in the months leading up to, during, and after the pregnancy can affect not only the mother, but also the child–and if that child happens to be a girl, that girl’s store of oocytes as well. Look up epigenetics for a sample of what I’m talking about.

So if I eat Soylent as my exclusive diet, what effect does that have on me, on my children, on my grandchildren? What bioaccumulative effects will only start to show up 50+ years into that regimen? I don’t know. You don’t know. No one knows.

I don’t THINK that Soylent is a problem, but I’d rather not risk even the slightest possibility that Soylent might be the next Thalidomide, you know what I mean? No one ever wakes up in the morning and says “You know what, I’m going to design, produce, and market the next catastrophic teratogen”. They’re accidental. The best of intentions don’t matter.

My questions are designed for my peace of mind, but they’re also a warning: these are the things you have to keep in mind when you’re effectively tossing out all of evolution and replacing it with something “new and improved”. Margarine was “new and improved”. The wheat being mass-produced today, dwarf grain or whatever. That’s “new and improved”.

There’s a fine line between scientific progress and folly. I’m aware that scientific progress cannot happen without (lots of) risk, but I think, with Soylent, we might be biting off more than we can chew.


“But the notion of trying to figure out exactly what it is that we physically require and foregoing great taste for it in exchange for convenience and lower cost while simultaneously optimizing health (or always striving towards that at least) seems like a pretty good idea to me.”

I completely agree. Which is why I was so disappointed to see Soylent being marketed at costs that actually EXCEED my current grocery budget over the same time period–and that’s with me eating paleo, ie, mostly ridiculously over-expensive food due to it being organic, raised without hormones, grass-fed etc etc etc.

I’d be VERY interested in trying out Soylent, even with all the objections I mentioned above–but not if it’s MORE expensive than what I’m currently eating. That’s just insane. The marketing for Soylent went from saying it was cheaper to saying it was more value for the amount of nutrition you’re getting. Which is only a way of saying “well, we made it lots more expensive, but it’s still worth it because of (insert factor we don’t actually have any supporting data for)”.


Andjay, I’m going to have to dispute a couple of your points. This may seem pedantic or semantic but at heart I don’t think it is. You talk about how certain things are “meant” to be, such as how fruits are meant to be eaten by larger animals or that wheat is meant to be wind-blown. To me “meant” sounds like intention and/or design. I don’t see any of that. I think instead you are just describing how things were in the past and some of the consequences it had.

So yeah, larger animals eat fruit and the seeds pass through their digestive tract and go back into the landscape in the middle of a fertilizer pile. So the animals get the benefit of the fruit nutrients and the fruit gets the benefit of its seed spread around. Fine. That’s to the benefit of both.

But being for the benefit of both is one thing and being optimal for one or the other or both is something else entirely. Just because something is being accomplished doesn’t mean it is being accomplished in an optimal manner.

The best way to spread fruit seeds definitely isn’t the way fruit plants have historically done it, since humans can now do it much better. And it would amaze me if the best way to get the necessary nutrients into the human body was by eating whatever plants happened to be growing nearby. The plants obviously have to be good enough to keep you going since if they weren’t we wouldn’t be here. But they don’t have to be anything beyond that.

Evolutionarily speaking, it’s only an advantage if something keeps you alive long enough to reproduce as much as you want to reproduce. But with respect to lifespans in the modern era, reproduction is pretty much irrelevant, in developed countries at least. At this point we’re not looking for foods to keep us alive from 20 to 50 to span our reproductive years, rather we’re looking for foods to keep us alive from 70 to 100. If a food did a great job in the past of keeping us alive up to age 50 and then harmed us badly after that age then it would’ve still been a useful food for us in the past. But not now.

Lifespans way back when were much shorter than now. Why? Well you can analyze the reasons but it all boils down to, we live longer today because we’ve figured out ways to live longer. The way we did things in the past wasn’t optimal, rather it was good enough to keep us going. How we do things now isn’t optimal but it’s good enough and it’s better than how we did things in the past.

We’re learning and we’re getting better as time passes. But still people sometimes die for no known reason even if they do eat whatever diet we currently deem best. So when people say “I don’t think you should eat Soylent because bad things could happen” I think to myself, “Bad things are already happening and the question isn’t whether bad things will happen if you eat Soylent but rather whether the rate of bad things will change if you eat Soylent.”


This is beautiful, almost a manifesto of my belief system :slight_smile: (seriously)


When I say “meant to be” I mean, in the same way that chemistry describes how the electron “wants” to bond with this chemical rather than that.

What actually happened is that the seed that just happened to develop the traits for this or that became more evolutionarily advantageous and so tended to become more commonly reproduced. But we use the term “meant to” to denote the more specifically accurate evolutionary description.

The best way for fruits to spread their seeds according to the limits of their evolved capabilities to do so is what we had before we started, for lack of a better term, “interfering” with agricultural practices. As a result, I imagine that certain traits have been dropped, and others added, because the trait’s “budget” tends to hold onto traits only so long as they are useful, which is to say, only so long as they are successful. If they are not (and sometimes even if they are) evolution is a process of trading in one trait on the blind chance that the new traits make up is more advantageous because of one reason or another.

Very simplistically speaking, the best “way to be” is a target. Evolution is a shotgun.

I disagree with your sentiment about what constitutes an advantage. I would change it to, evolutionarily speaking, it’s only an advantage when that trait interacts with one’s circumstances in such a way as to produce greater opportunity to reproduce, and/or to ensure the viability of one’s offspring. You mentioned being pedantic–in arguments of evolution, I believe pedantry is an advantage :smile:

Just as an aside, a large skewing factor in average lifespan was the high rate of infant/child mortality. If you have a large population of children (where age approaches 0) dying, then if our adult population is dying at 70, then the average lifespan approximates to 35.

Your argument re: bad things happening, I tend to agree with. In fact, my original questions regarding the science of Soylent revolved around that premise. Lacking an answer to all of those questions, and being a cautious and skeptical person by nature, the question morphed somewhat to the “I don’t think you should eat Soylent because bad things could happen.” With the caveat that, if those bad things are going to happen, I think I’d much prefer the details of those bad things to be recorded in case studies instead of lost in a labyrinth of anecdotal forum discussions. It is ABSOLUTELY TRUE that science requires practice runs. Otherwise, we would never have a space launch blow up on us. If we could control every factor, we wouldn’t need trial and error. So I’m not against the trial of Soylent–not even with all my objections I’m not. I think it is very worthy of investigation. But I think the investigation is something that I, personally, will wait for before I jump on board.

The cautious say “fools rush in”. The innovators say “only the early bird gets the worm”. Both are truisms, which is to say, they are 100% true within their specific contexts. You taking the innovator’s side is an absolutely valid standpoint, and I wish you luck in your endeavours. In the absence of trial data, I would of course prefer anecdotal data to nothing, but I prefer to hedge my bets a little.


With the exception of the sucralose and vanillin, everything in Soylent is found in normal food in some form. So if the foods it is made from or mimicking the nutrients if is good enough for us, then Soylent is too. Soylent may not be perfectly optimized, but neither is anything else you eat.

Additionally, evolution promotes whichever traits increase the rate at which traits are passed down. Those traits don’t necessarily lead to optimal nutrition for us, just possibly traits that encourage us to eat them. So food is not automatically better. I’d argue that Soylent is likely no worse than any other monotonic diet, on average.


Ok, so from having browsed these forums for a while, i have read the answers to a lot of these. You should probably read a bit more before asking everyone to serve up the answers. I can;t be bothered doing the leg work, so i will tell the answers i remember, and you can verify if you feel like it.
1a) Yes, most of the forms of the vitamins have been selected based on absorption efficiency, with one or two (I think choline and vitamin K were two of them) being chosen for supply and cost, even though a slightly better absorbed version is available There was no huge difference though.
1b)Time taken to eat - the same as any food. You can do it faster, and the body copes, or you can do it slower, and the body copes. Because it is fiber-rich for its consistency, however, it can pass through the system faster than your guy flora are used to if you chug it, and may cause flatulence when intestinal bacteria enjoy breaking the fiber down though,
2a) Yes it has. These competing nutrients like iron and calcium don’t usually come into play unless you take your whole RDA in a tablet at one time, and with Soylent, that doesn’t happen, the levels are low enough to not interfere with each other. In regards to complimentary nutrients, who cares. You get your RDA, and if there was something complimentary enough to boost absorbed levels over that, the dietitian on staff would have brought it up.
3) Too much work. Look it up, and let us know the answer when you do.
4) It is intended as a “Go to food, thought of for food like tap water is for thirst” (paraphrased badly from Rob) for when you don’t want to think about what you are going to eat, That depends how much you enjoy food and making it. If you are a foodie, it might just replace breakfast when you wake up tired, or if you don;t like making food, it might replace most of your meals with perfect nutrition.
5 - Yes. Soylent contains a lot of oats, which are the primary source of most people’s resistant starch in the modern diet. Rob learnt his lesson during trials, when he replaced oat with maltodextrin, didn;t add fibre, and ended up being unable to digest normal food for a while until he developed gut flora again. The current soylent contains oats and a fibre blend that meets the RDA (most people only get half of this).
6) The main issue that gives people’s GI tract trouble with soylent is that it contains as much fibre as they should be getting, and their gut flora isn’t used to it. To develop healthy gut flora, i have read 1-3 weeks on average, but some people continue farting for ages, possible due to not handling the level of sulphorus amino acids in rice protein well.
Lastly, with the guinea pig thing, i have known people to live for years on only jam sandwiches, or McDonalds. Soylent is a food, and it may not be perfect yet, but no one’s diet comes within even 30 percent of perfect most days (Yes, even hippies and nutritionists). The ingredients in soylent are all in other foods, and are safe, yes you haven’t had them in this recipe before, but that doesn’t make you a guinea pig any more than you are whenever you try a new food.


Well, to respond, I spend about 10 straight hours on these forums, reading everything that looked promising and I failed to find any of the responses you seem to have come across.

But I am glad that you have said it’s OK. That puts all of my fears to rest. If anyone else has any issues, don’t worry, datsagrindle says you’re fine.


It can be a bit of an art form to find forum posts when they don’t use the same wording you do. But props for putting in that much effort. I usually give up before even reaching half an hour.


What is with the sarcastic rudeness? You asked for answers, i gave you what i could. If it is because you couldn’t find information, i apologize. Here are some links to relevent information.
1a) You will have to enter the words “soylent vitamin” into the search bar, then you can click on the vitamins that people have opinions on, and read the evidence for and against the various types (this is also interesting on the topic)
1b) doesn’t really need evidence because “can food still get absorbed if you eat it quick” doesnlt really count as a question. (explains the effect of eating food too quickly)

2) (self explanatory)

  1. (about 3/4 of the way down, rob talks about his opinion of what soylent should be)
  2. (oats contain resistant starch) (Soylent contains lots of oats)
  3. put the word “experience” into the search bar. see how long it took for people to adjust


I imagine there could possibly be more examples similar to the above, but we haven’t found them yet. Or not. So I’d say the answer is “Not quite, but I believe that is one of the implicit long term goals.”; Soylent is still a WIP, after all.