Isomaltulose in Soylent 1.4

First of all, 1.4 should be called 2.0; this is not a minor update!

I am concerned about the amount of isomaltulose in 1.4. It’s made up of 1 glucose and 1 fructose just like sucrose, right? I wonder if it will have the same negative effects that Dr. Lustig talked about:


Isomaltulose increases blood sugar slower and to a lower peak than sucrose, making it deliver energy in a smoother curve and spike blood sugar less. The expected Glycemic Index (GI) for isomaltulose is 32.


The version number is correct. They didn’t completely scrap the old recipe and start over. This is a major update, hence the 1.4. If it was a minor update it would be 1.3.1.


The fructose in Isomaltulose is metabolized the same as in sucrose, so yes, you should be concerned.

It’ll have the same impact on your liver as drinking 3-4 shots of alcohol daily would. After my supply of Soylent 1.3 runs out, I’m going to be switching to DIY. :[

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That study you linked to makes Isomaltulose sound pretty good. If you really want to prove your point you should also link to a study showing that the amount of isomaltulose in 1.4 is the equivalent of “3-4 shots”.


The effects on the liver are covered in the video that @fumoboy007 already linked to.

Here’s another great video that covers the dangers of sugar:

Youtube is full of alarmist and quackery videos.

Fructose alarmism is especially popular right now, but that doesn’t mean it’s especially true.

The improvements in 1.4, including the addition of isomaltulose, have me considering going back to Soylent instead of DIY.


First of all, I did not reference all YouTube videos talking about this topic; I referenced just one, which is a recorded lecture of a professor who backed up most (all?) of his claims with solid evidence and used logical reasoning to argue his point.

Yes, popularity does not entail truth. Indeed, popularity does not entail truth nor falsity. But the reason why there is all this commotion about fructose is because science is telling us that fructose is bad for us.

I just wish someone from the Soylent advisory camp would simply chime in on things like this and put them to bed. Instead, we have threads that devolve into endless bickering and speculation and often worse, until it eventually gets locked. I think it’s valid for people to bring up issues like these, but then they should be able to be addressed by someone from the company, not just from other consumers.


You guys might find this link interesting. They said that the liver was not negatively impacted, if I’m reading it correctly. I really doubt that Rosa Labs is misleading us.


An interesting old quote:

1.4 now includes more than 42g per day isomaltulose.

The bitter truth about fructose alarmism. Here is a link to an interesting article that tries to refute some of Dr. Robert Lustig’s claims about fructose. Dr. Lustig himself makes several comments in the comments section of the blog.

Here is a second link that tries to summarize the comments and the dialog between Dr. Lusting and the blogs author Alan Aragon
A retrospective of the fructose alarmism debate.

Here is the summary from the bottom of the article:

I have a great deal of respect for Lustig’s professional accomplishments, and I share his concern for the nation’s penchant for sitting around and overconsuming food and beverages of all sorts. However, I disagree (as does the bulk of the research) with his myopic, militant focus on fructose avoidance. He’s missing the forest while barking up a single tree.

So, what’s the upper safe limit of fructose per day (all sources considered)? Again, this depends on a number of variables, not the least of which are an individual’s physical activity level and lean body mass. Currently in the literature is a liberal camp reporting that fructose intakes up to 90 grams per day have a beneficial effect on HbA(1c), and no significant effects are seen for fasting triacylglycerol or body weight with intakes up to 100 grams per day in adults [15]. The conservative camp suggests that the safe range is much less than this; roughly 25-40 grams per day [19]. Figuring that both sides are biased, the middle figure between the two camps is roughly 50 grams for adults (I’m talking about the general population, athletes with high energy demands can safely consume more).

Although the tendency is to get hung up on the trivial minutia of an exact gram amount, it’s not possible to issue a universal number because individual circumstances vary widely (this is a concept that baffles anti-fructose absolutists). The big picture solution is in managing total caloric balance with a predominance of minimally refined foods and sufficient physical activity. Pointing the finger at fructose while dismissing dosage and context is like saying that exercise should be avoided because it makes you fat and injured by spiking your appetite and hurting your joints.


This is the only reference to liver function that I see in that article:

Routine biochemical and standard clinical measurements for the assessment of renal and liver function, clotting (prothrombin time and partial thromboplastin time) and blood cell counts were not significantly different between both the treatments. The values remained in the normal range with both interventions (data not shown).

Unfortunately, they’re just saying that there was no significant difference between sucrose and isomaltulose with those tests. That is, they were testing 50g of daily sucrose vs 50g of daily isomaltulose, over a period of 4 weeks.They do claim that values remained in “the normal range”. However, it’s unclear what that is, and they didn’t provide any other information regarding liver function.

I haven’t seen any studies that claim fructose is metabolized any differently with isomaltulose than with sucrose, so it’s safe to conclude that isomaltulose is as “safe as” sucrose (in regards to fructose).

So really, it all boils down to if you consider sugar safe or not.


I wonder the number of nutritionists visit these forums and/or purchase Soylent or otherwise very knowledgeable about nutritional science. You would think that if the use of this sugar was such a bad thing that you would have seen numerous people turn it into a controversy. I don’t think Rosa Labs would successfully be able to “pull a fast one” on all of us without it becoming a major issue.

So far, all of these pubmed links have been suggesting just how safe and effective Isomaltulose is. We have people in Japan using it for nearly 30 years so if there was some negative long term effect then we would have seen it by now. Whenever I start seeing youtube videos, that’s a sign for me that the opposition is desperate. If Isomaltulose was such a health risk then it should be pretty simple to demonstrate it.

Time Magazine did an article about the war on science. It reminds me of that article whenever I seem this type of alarmism.


I didn’t claim you referenced all of YouTube… but you did reference the person who is probably the most popular fructose alarmist out there at this time. You can find a popular proponent of any position lecturing on the subject on YouTube.

Dr. Lustig does refer to the science, but his conclusions aren’t well-enough substantiated by the evidence he presents, and are contradicted by other evidence in the research. People better at this kind of analysis than you or I have picked through the details and drawn this conclusion.

@casssax’s post quotes one such researcher, Alan Aragon, but there are a great number of people in the field - including substantially all dieticians - who will agree whole-heartedly with the position Alan lays out in the quote Casssax provided, and will disagree with Lustig’s fixation on fructose as the main culprit.

In my opinion, after doing an awful lot of reading and research, most camps are excessively fixated on the problems caused by overeating their particular villain - whether it be fructose, or sugars generally, or cholesterol, or fats generally, or whatever - versus the fact that the overeating is the problem. The vast majority of the research shows that when we don’t overeat in the first place, the body does a really good job of staying healthy on a wide variety of sources in a wide variety of ranges.

Put simply: when you overeat, the things which have the biggest excess in your diet are likely to dictate the kinds of problems you develop. But if you don’t overeat, those same things are unlikely to cause any problems, as long as they’re within wide but reasonable levels.


Great post, and I couldn’t agree more. I just felt that I should add that it’s not just with alarmism - it’s also with the flip side. The “pro-” side is often just as bad as the “anti-” side. The internet is largely pedantic and overflowing with googlectuals.


You say this as if the alarmist weirdos could actually be swayed from their opinions. Tark is still going on about how rice is Satan incarnate.


All this stuff about how bad fructose is… it is true in high amounts that it can cause problems with the liver and more… but I doubt that the amounts in Soylent 1.4 is anywhere near those levels… Lets stop talking about if it is bad for you are not… and talk about how much is okay and how much is not… the dose makes the poison in almost all cases… and just saying something is bad for you is “stupid”.


Sigh… yeah I suppose that’s true. But it would at least be nice to be able to point to an official statement and say “take it up with them”.

Hey now - rice is awesome - how else am I going to get my daily recommended dose of arsenic?


Alarmists will be alarmists, no matter what.