Soylent and Sucralose: A Study of Artificial Sweeteners in the New York Times


On September 17, 2014, an article appeared in the New York Times about the probable dangers of consuming artificial sweeteners. This article directly relates to the use of sucralose in Soylent. Because of this article, I most likely will not reorder Soylent. While I still believe in Soylent’s mission, I no longer trust the efficacy or safety of its ingredients. Come to your own conclusions…

Just started my Soylent. This is Scary!

I agree; it is very disappointing that Rosa Labs opted for sucralose in Soylent instead of sugar.

I always put sugar in my coffee, never Splenda or any of that crap, for this very reason. I knew artificial sweeteners are bad for you, and sugar (in moderation) isn’t – this isn’t news, even though people keep acting as if it is.

Unlike maltodextrin, this is an easy fix – swap the sucralose with sugar. That’s it.

Someone somewhere on those forums mentioned a possible reason as being marketing – sucralose looks better than sugar on the food label for “certain people”. I find that extremely sad – something like Soylent compromised because people are stupid.


This is disheartening to say the least; I hope Rosa Labs will be addressing this soon.


This has come up in a couple of other threads already, and most of the discussion has been in this thread… and your link is no good.


The other thread covers this better, but the new information just explains some of the mechanism, and further confirms, an already known effect- consuming very large amounts of artificial sweetener in zero- or low-calorie foods causes glucose intolerance.

There is, as yet, no clear evidence that consuming foods with plenty of calories that are also artificially sweetened does so.

Basically, avoid any diet soft drinks, et al, they’re bad for you, and limit use of sweetener on its own, but Soylent is probably fine.

Which is not to say Rosa Labs shouldn’t investigate it, and strongly re-evaluate its use, of course.


Instead of sucralose, why not stevia? That one is more “natural” isn’t it? I’m assuming they don’t want to go with straight sugar because then you are adding calories and instead of 2500 calories or so per day, it would be closer to 3000…


… or what about organic honey? Add just barely enough to get rid of the so-called bitterness. The tiniest amount so that Soylent does not taste sweet whatsoever.

From Dr. Oz:

Over the past few months, I’ve become increasingly concerned about a sweetener that I’ve recommended on my show in the past. After careful consideration of the available research, today I’m asking you to eliminate agave from your kitchen and your diet. Here’s why.

We used to think that because agave has a low-glycemic index and doesn’t spike your blood sugar like regular sugar does, it would be a good alternative for diabetics. But it turns out that although agave doesn’t contain a lot of glucose, it contains more fructose than any other common sweetener, including high-fructose corn syrup. Initially, we thought moderate amounts of fructose weren’t unhealthy, but now we know better.

When you eat fructose-rich agave, your body does not release nearly as much insulin as it does when you eat regular sugar. This can affect how your body releases a hormone called leptin, which helps to control appetite. At the same time, experts believe that fructose is converted into fat more rapidly than glucose is. This can lead to several alarming consequences. The first is that people who eat a lot of agave are at risk for weight gain, especially belly fat. The second is that agave may actually increase insulin resistance for both diabetics and non-diabetics.

In addition, fructose poses a danger to your cardiovascular system and could increase your risk for metabolic syndrome and heart disease. Unlike glucose, fructose can only be broken down in the liver. As it gets metabolized, uric acid and free radicals form, which can trigger inflammation and damage cells. Plus, one of the most dangerous final products of fructose metabolism is triglycerides, which can contribute to the fatty arterial plaques responsible for cardiovascular disease. High triglycerides are particularly dangerous for women, whose risk for cardiovascular disease rises three times as much for every single unit increase in triglycerides compared to men.

But fortunately, agave is not the only natural sweetener you can turn to when you have to satisfy your sweet tooth. Raw honey has less fructose than most agave and is the only natural sweetener with other health benefits, which include anti-microbial, heart-healthy and anti-inflammatory effects. It has even been shown to help soothe a cough as well as, if not better than, many over-the-counter cough syrups. I love honey so much that I even harvest my own, but you can find raw organic honey at your local supermarket. However, keep in mind that no infants under the age of one should eat raw or pasteurized honey.

As always, the safety and health of all Americans is of the utmost importance to me. After learning about the risks high-fructose foods like agave may pose, I knew I had to speak up and alert you so that you can turn to healthier alternatives like honey. In the future, if you have to use agave, I urge you to use the smallest amount possible.

  • Dr. Oz


I’m not particularly worried about the sucralose. My diet pre-Soylent was probably poor enough that any damage sucralose could potentially do is minimal in comparison…not that my diet was horrible…

That said, I do think stevia or honey could be good alternatives, but I don’t know what difficulties might be inherent in including them in the product instead of sucralose.


“Natural” is an arbitrarily chosen marketing term of art that has no real value proposition as a food descriptor. Methane gas is natural. So is gamma radiation, or uranium, or kitten fur. Stevia extract has about the same amount of processing.

Sucralose is a flavoring agent. The effects in the study can’t be isolated to, but serve as evidence of changes in the gut flora of the mice resulting in glucose intolerance. Enzymes triggered by the flavor of sweet without the corresponding glucose to digest are the probable culprit. These enzymes will favorably impact the growth of certain bacteria, which then translates to a glucose intolerance.

The effect is in isolation, consumed with water rather than a comprehensive nutrition source. I would say that the rational takeaway from this is to not mess with the body’s regulatory perceptions of food - don’t trick it into thinking that you’re eating something, triggering metabolic responses, when you’re consuming a calorie free substance. If you’ll notice, the mice drinking sugarwater didn’t display negative effects.

What they should do as a control is to test macronutrient sources - sweetened and unsweetened carbs, oils, and proteins, and non-nutritive fiber/filler , both soluble and nonsoluble.

The effects of vitamins and minerals may also play a part, as you’ll see bacteriological responses, so those should be kept to a uniform basis. Once the controls are set, you could easily change the variables to see the different effects and calculate the functions for each nutrient, rather than testing just sugar water.

This is fuzzy science, but gives a decent insight into the major effects of gut flora on metabolism.


Pardon me if I’m repeating what other people are saying, since I’ve not read all of the comments, but as far as I know this mechanism of artificial sweeteners has been observed for at least the better part of a decade. If you trick the body into thinking it’s receiving sugars when in fact it is not (low-cal soft drinks et al), then you gradually mess up your body’s ability to regulate your blood sugar. As far as I know, none of the studies that have seen publication have introduced it in small amounts as a supplement with other meals, in which case the body would be triggering insulin to counter a spike in blood sugar and working as intended. That sort of study would be more difficult to control for than just spiking the drinking water, but there’s a very different effect going on.

Soylent uses artificial sweetener purely as a sweetening agent, but it contains many carbohydrate calories and other users have measured - using blood analysis - a significant spike in blood sugar levels after consuming Soylent. If the effects of artificial sweeteners are understood correctly (so far we just don’t know the full effects, though the findings always seem to correlate glucose intolerance and metabolic syndrome specifically with the use of sweeteners in the absence of sugars), then you’re probably well in the clear when it comes to Soylent.

Stevia has some of the same characteristics of artificial sweeteners. When refined, it’s claimed to be about 200-300 times sweeter than table sugar by volume. “Natural” or not, I suspect that using comparable quantities of Stevia in low- or zero-calorie beverages as a sweetener would result in the same effects in the aforementioned study.

Of course there’s still always the chance that sucralose is evil and toxic and carcinogenic etc, but this study hardly proves it


The novel part of this study, though, is the discovery of a potential mechanism - gut flora - as that hadn’t been known before. We know for a fact that your body reacts to the taste of sweet, but how those reactions translate into dysfunction or harm hasn’t been proven. So if it is gut flora, then determining how to avoid the effects- let’s say sufficient carbs to deal with the digestive enzymes, so as to not put your microbiome out of balance - then we have a cure that’s easy to implement. It could also be as easy to supplementing the right probiotics.

If it’s not gut flora, then it’s something that consequentially affects them.


If all-natural-sweeteners are a valid goal, then honey is a valid option.

A friend just gave me some freeze-dried-to-powder honey. It is very tasty and as a powder would co-exist with all soylent (small s) powders quite well. However it’s still a sugar.

If you are trying to stay below what Dr. Robert Lustig calls the “sugar tipping point” honey is a risk. Lustig’s theory is that when you eat more than your daily needs for sugar (don’t forget all carbs become sugar) then your liver usually decides to “bank” the excess sugar as fat.

It is a very interesting theory that tests well in practice. He’s got some vids on BookTV and YouTube.


Fat Chance is a fantastic book and he has a lot of good insight on metabolic syndrome. Here’s one of his more popular Youtube talks posted prior to publishing the book (though the book feels less like alarmist fear-mongering due to the more-detailed body of supporting evidence) -

SO much of nutrition is a black box, though. I personally think understanding gut flora will have a huge impact on understanding our bodies, but currently it’s all correlation and speculation. The effects of sugar and insulin on the body are much more well-established at this point. Not to say that we shouldn’t put stock in new science, but it’s unwise to discard what we’ve already observed until we have sound reason to.

If nothing else, I’d put more faith in Lustig than I would in Dr. Oz (though it seems that Oz is taking a page from Lustig from the post earlier in this thread re: the metabolism of fructose).

An unrelated-but-very-fun reading suggestion for anyone still reading: Mary Roach’s "Gulp: Adventures on the Alimentary Canal"


As was mentioned earlier this study gave the sweetener in the absence of any caloric intake. While this may be significant for someone living solely on diet soda the results may be different when an artificial sweetener is used as a substitute for glucose or fructose in a food product (i.e Soylent) where there is an abundance of calories for the gut bacteria to go to work on. Without a follow up study designed with a mix of caloric rich food along with the sweetener I am in the camp of the jury is still out.


It’s actually NOT that simple, of course. Sugar changes the glycemic index, and also (obviously) adds calories, which is why they went with sucralose in the first place.

Stevia would probably be a better option.


Stevia is likely to exhibit the same effect as sucralose.

And using sugar to replace some of the maltodextrin would reduce the glycemic index, not raise it.

But this is all an overreaction. The effect is small - the study was done on saccharine because the effect is largest with saccharine. (EDIT: Deleted false reference to this effect only applying when there are no calories.)


… it is likely to only happen with calorie-free drinks. Soylent is calorie-full food.

Are you sure? What evidence do you have? I am not trying to be contrary but maybe surcralose will cause problems whether the stomach is full or empty. Like I said before, these questions and concerns are a matter of life and death. We look to consume Soylent as a solid food alternative. Soylent is what gives us our life force. It better be perfect or we will all pay the price.



I’ve finally had time to read the original study with a little more care, and I rescind my earlier comments that this effect seems related to using artificial sweeteners when there are no calories coming. In fact, the study did work to show that saccharine has an effect directly on the bacteria in question. Enzymes probably don’t enter into the equation at all.

I’ve chopped out my comments to the contrary from the post below, and did some editing, so people reading this in the future don’t get false ideas from me.

The main reason this study is so interesting is because this whole glucose-intolerance effect of non-calorie sweeteners has been so incredibly hard to pin down. There are multiple studies failing to point to a cause or even an effect; there are lots of studies showing no effect and no danger. This is common when the effect in question is relatively weak and there are a lot of processes in play.

This study finally narrowed down the processes in play enough to elicit a clear enough response to measure, and clearly shows that the glucose intolerance effect is tied to the bacteria. (They successfully transferred the glucose intolerance to mice who never had aspartame by transferring those bacteria into them. They also cured mice of this kind of aspartame-induced glucose intolerance by giving them antibiotics to kill all the bacteria, and then letting new bacteria grow in. So the glucose intolerance is strongly linked to a change in the bacteria, not a change in the mouse.)

For that matter, since this study only used saccharine for most of the work, it’s possible that the milder glucose-intolerance effect of sucralose isn’t tied to the bacteria, but it most likely is. More study and understanding on the mechanisms will make that clearer.

We do know that sucralose and saccharine and aspartame all produce a glucose-intolerance effect. This study focused on aspartame, which seemed to have the strongest effect of the three, and then clearly connected the effect to an induced change in the bacteria.

It’s hard to contrive many ways for all three of these very chemically different substances to induce a similar chemical change in the downstream bacteria… the strongest candidate is to consider their one common property: they all set off the body’s carb detectors on the tongue. That is, they all have properties that make them detectable as “sweet.”

Do the bacteria have a similar “detection” chemistry? Is that what’s leading to the changes?

If so, we should expect the same effect from stevia, or other natural sweeteners. This may be an inevitable effect of all or most “non-calorie” sweeteners. I don’t see any strong reason to believe this is only going to happen with “artificial” sweeteners.

Don’t think I’m anti-stevia; I’m not. I buy it in bulk; I use it in my coffee, my tea, and my DIY soylent. But this study gives me every reason to think it has the same effects as the other non-calorie sweeteners.


No. No, they are not.

They are a matter of a weak glucose intolerance effect that appears when consuming fairly large amounts of artificial sweeteners.

No. It does not need to be perfect. It needs to be better than the solid foods it’s replacing. For most meals, it is demonstrably better.

We didn’t survive as a species for the past one hundred thousand years because we were eating perfect food all the time. We survived because we were capable of surviving on a wide variety of marginally adequate foods for long periods of time. When you look at the archaelogical evidence, the most startling thing about us is the extremely wide variety of things we managed to thrive on.

It is our adaptability, not our specificity, that is most remarkable.

There is no perfect food. You’ve never eaten a perfect food, and yet you live.

You’re thinking of midi-chlorians.


MentalNomad, thank you for your sober, non-confrontational, and very intelligent reply. Your knowledge is exemplary and there is quite a bit that you said that makes sense. I am not a chemist nor a doctor and my dietary decisions are based on studies like the one here but also on informed responses like yours.

With that said, I am still not convinced that sucralose is safe, however, your more informed opinion is that sucralose is a safe and effective ingredient in Soylent. You also seem to say that the science really isn’t conclusive one way or the other. So wouldn’t it be better to be safe than sorry and leave sucralose out of Soylent?

Furthermore, isn’t there a better alternative that most doctors would agree on is a better sweetener for Soylent? ( I suggested organic powdered honey?) Better yet, isn’t there a way to make Soylent less bitter without sweeteners altogether? I believe this last suggestion would help convince trepidatious people like me that Soylent is a safe and viable food alternative and increase sales for Soylent.