My friend works for the FDA, so I asked him about Soylent


A friend of mine is a staff economist at the FDA who sometimes works on nutrition-related issues, so I asked him for his thoughts on Soylent. This is what he said:

This could be a useful product for a lot of people. It would probably be an excellent emergency meal, and is clearly better than most types of fast food or protein shakes. But do not forget that it is basically just protein powder, grains, and chemicals. If you tried to live exclusively on it, bad things would probably happen. Bioavailability is important, There are a lot things that are good in their natural form but worthless in supplements like this. But if you lived mainly on this and also ate a salad a day along with it, you would probably be fine.

For context, I should mention how science discovered and defined the essential vitamins and minerals. They are things that cause obvious and damaging diseases if your diet lacks them over the short to medium term. I suspect that there are many other semi-essential things whose absence could cause small problems, or large problems over the long term. Soylent starts with simple stuff and adds the known essentials. If you tried to live on it for years, you would probably develop a new and interesting nutrient deficiency disease.



I think it will be really fascinating to see all the new things we discover about ourselves with Soylent.

I haven’t heard of many people who intend to do long-term exclusively Soylent diets, though. It seems even the most fanatical have a couple real food meals a week. I don’t think it’s something most people will have to worry about.


I think your friend has a good point. We all should recognize that as much as experts and every test we can think of have shown that Soylent should be nutritionally okay for us, we’re all doing an experiment that hasn’t been done before. (at least with this mix–other tries at a nutritionally complete food don’t really have much bearing on this try; even if they didn’t work out, that doesn’t mean that Soylent won’t, or that it will)

Let me repeat: we’re all doing an experiment here; we’re doing science. This his how new things are discovered, so keep an eye on your health, pay attention to what your body is telling you. Maybe we’ve already isolated all the required elements, and maybe we’re missing one. Soylent 1.0 might let us detect that one missing one, and add it into Soylent 2.0, which then is complete. We just don’t know yet. The only way to know is to try.


I do hope someone gets a deficiency disease. of some kind in the long term… that would be a breakthrough in nutrition science and we could adjust Soylent to account for it. (as long as it’s not something that causes permanent damage ofc. and would be fixed by getting what they lacked heh, don’t want anyone to die or anything)


Bioavailability seems like a pretty common criticism of Soylent. While the associated concept of " ‘natural’ nutrients are somehow better" is pretty well acknowledged as a fallacy, the fact that some compounds can affect each other’s absorption/use/etc rates is still valid.

As far as I can tell, it’s been pretty strongly implied (if not outright confirmed) that the ratios in Soylent have been heavily analyzed by Rosa Labs’ nutrition professionals, and explicitly adjusted for these bioavailability cross-effects. It would be great to get some more detailed insight/confirmation on that though – maybe a blog/forum post from @rob on bioavailability re:Soylent?


I think that most people will use soylent as a meal replacement (for example instead of breakfast or lunch) but will still eat other food, so the deficiency worries should be limited to those who plan on living exclusively on soylent


Which makes him pretty much just as qualified to comment on this stuff as everyone else. And then he retreads the same old ground that’s been beaten into concrete since the beginning now… I worked for IBM, but I’m not going to break out my opinions about how mainframes work. I worked for Verizon, but I’m not qualified to talk about cellphone coverage or FIOS bandwidth.

Yeah, 8 months ago when this started, that might have been new and fresh, but now, it’s just the same old stuff. People HAVE been living on this for that long, and tinkering with the recipes… pretty well showing that it’s easily possible, and while Soylent might have long term problems… so does every other food that’s ever existed. “Health is the slowest possible rate at which you can die.”


Bioavailability is important, There are a lot things that are good in their natural form but worthless in supplements like this.

I’d be interested if he specifically looked at Soylent’s ingredients, and thought that some of them were worthless, or if it was just a general “many supplements provide nutrients in useless form” observation.

If the former — interesting.

If the latter — then it’s a bit like someone telling you that you won’t like a movie, when they’ve only heard a vague description of it. They could be right, but there‘s not much detailed evidence behind what they’re saying.

In general, I’m really interested to see what benefits and drawbacks a Soylent-only or mainly-Soylent diet has.

I’m much less interested in hearing vague “your body needs ‘natural’ food” statements that don’t define “natural”, don’t explain why whatever I’m eating doesn’t count as natural, and don’t explain how to test for health drawbacks that they think I’ll suffer due to not eating whatever ‘natural’ food is.


Natural, organic, gluten free, 0% enriched uranium - the preceding terms are all about equally meaningful in regards to 99% of the population. Also… seriously. Chemicals?! OMG, YOU CAN’t EAT CHEMICALS!!

All snark aside, I doubt we’d see an unknown chronic deficiency at this point. Enough people have lived with decades of consistently poor nutrition that we’re not going to discover something essential, but beneficial. What we’ll discover is things that optimize health and well being. We’ll also discover optimal ratios, and a methodology of tailoring those ratios to your current health, body type, and genetics.


Well, in the long-long term (or int64 term I guess, if you want to be technical), there actually could potentially be an interesting detriment for those using near-exclusive Soylent diets: The human body has a track record of losing what it doesn’t use. Could that extend to our current, actually-pretty-incredibly-flexible system for managing nutrients? In other words, if you were to hypothetically spend 50 years eating exactly what you needed and nothing else… how would it affect your ability to go back, eat an unbalanced diet, and have your body still capable of more or less adjusting to it?

I’m honestly not quite sure on this. The question has been sort of voiced a few times around the forums, but I don’t know that it’s it’s actually gone into solid discussion. I… think I’m actually going to branch a new thread off of this, for a dedicated discussion on the topic.

"Use it or lose it" re: current human diet adaptability

Wouldn’t we just add those to Soylent x.0 as they’re discovered, if they’re discovered? Seems pretty easy to detect and mitigate with a fairly standard level of self-monitoring and communication with your physician.


Diesel engines can run off of unfiltered used fry grease. If you ran a truck on that for a year, and then switched to diesel that had detergents and over the course of the next year it “scrubbed” the engine again, you could still switch back to used fry grease. It’d run really well until it started to gunk up again. I’d imagine the human body is also like this.


This actually is an interesting analogy. However i think it falls short of the complexity and vast amount of knowledge of human physiology and the way it works that we simply do not know or understand.
Some of our nutrients are either created, broken down, provide to, or assisted with not by our bodies themselves but by the trillions of tiny “critters” that live in and on our bodies. How will all this floura and fauna be affected by a monotonous unchanging diet for “50 years” as someone suggested?
How will being on a monotonous unchanging diet affect the immune system?


If you stop having dairy for a few years, your body stops producing the lactase enzymes that are necessary for digesting the lactose sugars in dairy. So when you start eating dairy again, you’ll get the runs like mad, and perhaps even vomiting and other digestive upsets. However, if you persist and keep consuming dairy despite the discomfort, your gut bacteria will adapt and break down the lactose for you(it helps that your native bacteria intermingle with the bacteria brought in on the dairy) so that you can happily return to consuming dairy. I’ve done this myself. So yes, the body can re-adapt to some extent to its former diets.

As for nutrients that may be missing from Soylent unbeknownst to us…well, I used to think of Soylent as something like kibble for humans, in liquid form. But there’s a key difference between Soylent and pet kibble: kibble is made primarily from various “real” foodstuffs mixed together. Yes, Soylent has some “real” stuff in there, but the majority of its nutritional value is synthetic, so it’s far more likely to be missing some unknown essential nutrient than kibble is, since kibble contains a variety of unintended nutrients in addition to what pet food companies actually measure. 100%Food is more like kibble than Soylent, but even so it does have a pretty limited ingredients list compared to kibble. I’d like to see a liquid meal that resembles kibble more, as odd as that sounds.

EDIT: I should specify that I’m talking about the good high quality kibble brands out there, not the cheap ones that are basically corn plus vitamins lol


I’d say the opposite of “synthetic” in this case is not “real,” it’s “natural.” Specifically, synthetic nutrients are real nutrients, even though they are not natural. I also find the “unknown essential nutrient” argument hard to take seriously. I admit that it is possible, but I find it exceedingly unlikely. Especially the longer Soylent has been around without anyone taking ill or dropping dead due to Nutrient X deficiency (Rob lived on it exclusively for about a year, didn’t he?). If you go back and read the Soylent origin blogs you’ll see that actual nutrient deficiencies manifest rather quickly.


I used the word “real” in quotation marks to indicate that I wasn’t meaning it in the literal sense. I was hesitant to use the word “natural” because I thought I might get flamed for calling pet kibble natural. If you’d like to be fully literal, many synthetic compounds are also natural because they occur in nature; the “synthetic” part is just to indicate that we made it in a lab/factory rather than extracting it from natural sources.

I do agree that the potential for missing essential nutrients is not a serious threat, but it’s still a possibility. Soylent has only been on the market for just over a year, so there’s not a whole lot of data. Yes, the most important things will appear quite quickly, but it’s certainly possible for deficiencies or excess to have very gradual effects as well. For example, a kidney stone caused by some particular mineral excess could be forming for several years before it causes any pain that would indicate a problem.


I’d say a more realistic danger/expectation is that we might discover previously unknown and probably rare genetic mutations in some people that prevent them from processing nutrients in whatever form happens to be used in soylent at the time; similarly to how some people genetically have a more difficult time being vegan.


What about the chance that there is an ingredient or combination of ingredients that just happens to cause serious harm, and because Soylent has unusual ingredients in a few years we will discover that Soylent eaters have half as many cancers as the general population?


I though he only did Soylent exclusively for like 90 days or somesuch… but that he’s been 90%+ Soylent for easily a year. I could definitely be wrong, but that’s what my memory is telling me.


Me too @Prairiepanda me too.