What Happens When Mice Eat Nothing But Powdered Food


This is another small study. This one studied a few mice for a few weeks. Interesting, but probably not long enough or with enough mice to be of real concern? Interesting read in any case:


Reading through it, the only thing that stuck out was ‘no discernable difference’ in body mass or overall health.

The low insulin isn’t especially worrying, since Soylent seems to be best consumed in smaller sips that don’t merit a cascade of insulin, as would a large meal.

The other differences in blood
chemistry are interesting, I wonder if that’s a byproduct of the food stock. I’d love to see a larger sample size on future studies…


Not good, but since there are very few scientific studies yet, people will likely use this as evidence against Soylent.

Rob should commission his own study.


Probably not much point. The naysayers would just point to it being funded by Rob and call it biased, etc. You can’t win with those who will not accept any alternative to their existing beliefs.


One problem I have with comparing this study to Soylent, is that they are feeding the mice powdered food, but Soylent is not consumed in powder form it is consumed as a liquid. Infants go years eating liquid food only (although it is possible that if chewing triggers certain responses in the body, that nursing may trigger the same)

I’m also curious about the amount of food given to the different groups.

Blood glucose measurements in those mice suggested the mice’s bodies absorbed nutrients much faster from the powdered food than the solid stuff.

Could it be that the mice eating the pellet version of the food, don’t absorb all the nutrients in the food? If that is the case, and they are giving both sets of mice the same amount of food, the mice eating the powdered food may be getting overdoses of nutrients that the pellet eating mice are not.


To be fair, you’re dismissing a peer reviewed experiment that happens to disagree with your existing beliefs…


No actually I’m not. I was speaking of no specific study, I was speaking of the emotionally-charged naysayers who say “Soylent is bad because it’s not food” etc. Please quote me in context.


I don’t understand the logic here. If you chewed a steak long enough, it would be liquid food. and soylent is liquid food. So that means that the only difference is the amount of chewing required. And I dont think simply moving my jaw would lower my blood pressure and help regulate my insulin levels.


Isn’t that effectively what they are saying, that chewing in itself is a positive factor?


But chewing doesn’t have anything to do with chemical balances in the body.


I saw this and thought it was the first reasonable objection to Soylent I’ve seen so far. While I think the study certainly merits further research, I don’t see it as a definite problem so far for a few reasons. First of all, it’s a single experiment and needs to be replicated.

Secondly, I think there’s a problem extrapolating this sort of finding to humans. Historic human consumption is not only different from other mammals (like mice), but also different from other apes. We cook our food (which no other extant animal does) and we’ve been doing so for one to two millions years. Not only does this allow for us to have evolved to fit this behavior, but we’ve evolved so much in that time that we’re a different species from our australopithecine ancestors who began doing this. One important finding anthropologists have noted about cooking is that it vastly reduces the amount of chewing required to obtain nutrients. See, for example, this article. So, we know we chew less than other mammals (that’s chewing needed per calorie, possibly less overall as well), and therefore the negative effects seen in mice may not apply to humans.

Finally, if it turns out that the findings are replicable, and it applies to our species as well, this still doesn’t doom Soylent as a source of nutrition. Instead, it might suggest that it would be better prepared as a solid food, perhaps baked as a bread-like substance. Or maybe the recommended procedure would be to chew some gum just prior to consuming.

Overall, I think this sort of finding should be taken seriously, but I don’t see any basis for using it to reject Soylent outright.


You’re right when you say:

“Could it be that the mice eating the pellet version of the food, don’t absorb all the nutrients in the food? If that is the case, and they are giving both sets of mice the same amount of food, the mice eating the powdered food may be getting overdoses of nutrients that the pellet eating mice are not.”

I’ve seen the full version of this paper (linked in a post on reddit). It says: “Powdered food, even for such a short period, resulted in a greater glycemic response than pellet food, consistent with powdered food being more easily digested and absorbed.”

It also says “The groups were allowed free access to their respective type of food.”

This is basically equivalent to giving humans one normal buffet and one with powdered food. Even if people ate the same amounts, the nutrients from powdered food will be absorbed more. It is like saying that 100 grams of normal food is equivalent to 80 grams of powdered food.

So the study would have been valid if it was not “free access to Mice which cant make any decisions about food”. They should have been fed fixed carefully calculated amounts of both types of food and the amounts adjusted for absorption rate and so on. It was a biased incomplete study designed to purposely scare people from powdered food.


That’s simply not true (at least, not obvious enough to be taken as true at face value).
Macro-properties (such as “particle size”) simply ARE relevant in applied chemistry. Blow finely powdered flour into a small fire and you get a giant fireball. Dump a sack of it on a fire and it’s extinguished. Mix ground coffee in hot water vs dump beans in cold. etc… It’s crazy to think these factors don’t have an effect on nutrition absorption.

Disclaimer: Not a chemist, not a biologist, not a nutritionist, not against soylent (I’ve bought 5 wks). Just against unfairly dismissing ideas.


It’s important to understand that mastication (chewing) IS relevant. Saliva contains enzymes that help initiate the digestion of food. There’s more to your spit than just water. There’s peer reviewed scientific research validating the importance of mastication as relates to several relevant issues including nutrient absorption, digestion, horomonal response, and satiety.

Chewing gum right before eating soylent is an option, as is swishing soylent around in your mouth for a minute before consuming a few of the bites to activate the salivary response producing the enzymatic components. (These are particularly important for digesting carbohydrates.)

Not a scientist, and not packing a bunch of journals to quote for you right now, but you can check out The Journal of Medical Investigation as well as The American Journal of Clinical Nutrition for sources of peer reviewed articles on why mastication does have a direct impact on, among other things, chemical balances in the body.

That said, I have been on DIY soylent for a couple months now and have had no issues. I’ve lost weight, have improved cognitive repsonse with less/no caffeine, and my skin is looking healthier too. I don’t chew gum or swish my soylent. I just slam it down 3-5 times a day. This anecdotal evidence of course doesn’t really mean as much as the peer reviewed articles, but yeah. My 4 cents.


The importance of saliva on digesting soylent is unclear. Sure, it is useful for a steak, as there is a lot to break down and nutrients are tied up in various cellular structures. When the nutrients are already spread out in a powder with simpler forms, is that step still important? There is a lot more at play than “chewing” vs “no chewing” or “saliva” vs “no saliva”, and extending the results of this one study to soylent is almost certainly invalid due to the combination of extra factors, including the forms of soylent, human digestion, and factors unaccounted for in the base study.


It seems like it might!



My point is that, if you chew anything long enough, it’l be the consistency of soylent. so you’re receiving the food in the same physical consistency whether the food is powdered or not. so the chewing really doesn’t matter, all it does is add a step to the food eating process.


I think this study is replicable. But to me all it shows is that they managed to increase the GI by crushing food into powder … If you want to compare suger absorption this study is awesome but if you want to compare effects on health of liquid vs solid/raw food you absolutely have to start with different ingredients. I am really surprised at the amount of attention this thing has gotten but then again I am not a doctor so I might be missing something.
I found an interesting site that goes over all the ways GI gets effected: http://www.montignac.com/en/the-factors-that-modify-glycemic-indexes/


…but we don’t chew anything that long. not even close.


But if anything that means our body is unable to fully digest and absorb the nutrients, because there are bigger chunks of whatever food we just ate. I mean, if chewing is the difference in these studies, then chewing gum, and then drinking soylent would be the best nutrition in the world wouldn’t it?