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


Continuing the discussion from My friend works for the FDA, so I asked him about Soylent:

@rob, any thoughts on the above? I have to assume this has come up for you guys as at least a curiosity, and I’d be interested to hear any data you’ve dug up on how the body adapts to more or less efficient diets. Just on an anecdotal “big picture” level, I believe the human body now has greater trouble with raw meat and other foods more easily digested far back in history. Obviously a lifetime is a much narrower scope, but it seems like smaller changes in adaptability could feasibly still develop within the range of years. On the other hand, perhaps adaptability is, by definition, not something the body will “adapt out of”, and going back would be easily smooth after a minor transition phase. Either way, I think it’s an interesting topic.

Just to be clear – I’m not talking about the digestive system losing its edge and becoming less able to actually absorb nutrients. I’m talking about the body’s inherent ability to “pick up the slack” and adjust to a myriad of technically-incomplete diets with generally little to no deficiency symptoms. Soylent is certainly more healthy than most other things – but could the body come to depend on that high standard?


This is a very interesting question… I don’t really think that anyone could answer it objectively, but I would love to hear the discussion.


I agree that there is no likely answer at this point. I don’t personally expect adaptability to be lost. We are far too good at coping.

I would think though that if we did lose our ability to adapt, it would be individually, and over many years, by which point hopefully our myriad soylents would be so ubiquitous within our society that complete nutrition would be easy to accomplish and commonplace.

I also wouldn’t be concerned for instance that our kids would be born less able to adapt, at least not for very many generations. With the rate of technological advance the danger of mutation, if present at all, would likely be identified and addressed long before becoming a problem. Hopefully.


I wouldn’t expect adaptability to be “lost”, per-se. But a decrease in efficiency… maybe? If the body doesn’t have to put in as much work to harvest sustenance from a diet, will it come to depend on that easy, rich diet? The big catch in any study though is going to be subjectivity. Even if there’s no real physiological difference, there will almost certainly be a psychosomatic one when moving back to a diet that’s less readily nutritive.

A good parallel would be any existing research looking at whether people from areas of famine have a more “efficient” system than those living in relative opulence. Is digestive efficiency a system that inherently strengthens or optimizes in response to scarcity/hardship – and if so, does that imply the opposite as well?


I don’t doubt that moving off of a nutritionally complete diet would leave someone with a mental lag and the associated physiological effects for a bit, but the fog should clear quickly enough. I would think it would be similar to what you hear with those going into ketosis, it sounds like it is 1-4 weeks of unpleasantness, sluggishness, mood swings, molasses on the brain, etc, then back to normal once you’ve adapted.

I also wonder if there have been any anthropological studies on large people groups migrating. How adaptable they were to the new diets, and how long it took them to become fully able to utilize the change in diet without ill effect.

Presumably if a group were to move to a completely foreign region, their diet could change rapidly. Had they been on the same “beans & rice” diet for generations it would be easy to assume their bodies may adapt to thrive on those nutrients, but the new region may have them eating a diet of “fish & fruit”. I would expect them to adjust quickly, but I’m curious if there are any numbers on it.


It takes generations for these things to happen, no? Soylent could be the beginning of a new human, but for us old dogs, it wouldn’t mean much.


This makes me remember a study I saw once. It basically said that a poor diet on the parent’s part would influence the metabolism of their children. So, a mother who is going through a famine will produce kids with a slower metabolism to help them cope with the expected lack of food, and hence such kids raised in an area of abundance would be more prone to obesity.


I went 3 days with no soylent and had an over abundance (even more than pre soylent) of fast food :frowning: Still dont feel right. I felt sick for days all i could eat was soup and soylent.


It’s not exactly the same, but I’d suggest reading up on Lactase persistence for some insight on the genetics behind our digestive system and how some societies may have evolved the ability to digest lactose in adulthood due to the availability of animal dairy.


If that were true I wouldn’t be the stick I am today.


It is far from the only factor. It may not even be the most significant. But you as a single counterexample doesn’t mean its not a factor anymore than bob living a long life despite a family history of heart disease means that family history is not a factor in heart disease.


I know. I was just… grumbling? Sometimes I forget we try to do science here.


It’s important to see “use it or lose it” as the ephemeral statement that it is. Just because you lose it doesn’t mean it won’t come back if you need it (ie if you start using it again). I’m no doctor, but if something is so quick to change one way it ought to be comparably quick to change the other way.

Even if you did come to depend on the higher standard, it wouldn’t kill you to quit, it would just necessitate a re-adaptation to dealing with crap.


It’s also interesting to consider the effect that gut bacteria have on our digestive processes. I’ve heard from friends who stopped eating meat for a period of months or years and then going back to eating meat that they had a really hard time digesting the meat at first. I wonder if that has to do with their gut culture, and most of their meat-eating gut bacteria died of starvation while they were vegetarian, and then had to repopulate when they started eating meat again? Perhaps part of our ability to go back to more usual food after many years of Soylent might be assisted by bacteria transplants… :stuck_out_tongue:


You’re not totally wrong there…


Damn, @mclaypool stole the answer I was going to write. I was basically going to compare a long term Soylent diet to long term vegetarian/vegan diet because I’ve heard a number of anecdotal accounts of people having digestion problems/illness after returning to animal products/meat.

This is a fantastic thought, I would love to see a study (or series of) where researchers transport a number of people from essentially low nutrition cultures (like the Africa’s, for example) as well as a control group of standard western dietary eaters and gave them the same ample but balanced diet. Would the starving groups nutritional well being leap through the roof and they become as healthy as the westerners because their bodies have learnt to harvest all possible nutrients? Or would the changes come more slowly because they don’t have the ready biology to be able to digest the sudden increase in diet?


You would also have to consider the effects growing up with poor nutrition would have. It seems likely to me that some amount of damage is already done due to being malnourished during development, so even if they can utilize it well they may not reach the same standards of health.


Not sure if entirely relevant to this conversation, but I can’t really digest plants.

The only plants I regularly eat are rice and beans (and potatoes if you count French fries). I will also, rarely, eat apples and carrots. Pretty much any other plants just don’t seem to get properly digested. I’ll spare you the details…

I’m assuming that I’m missing or low on the needed “gut bugs” due to my extremely limited consumption of plants. Not sure if that would improve if I started eating more plants on a regular basis or if they’re lost forever.

I have a co-worker that’s a pescatarian (vegetarian + fish eater). He gets pretty sick if he accidentally consumes something with meats such as beef or chicken. I worry about losing the ability to properly digest meat if I were to go on a Soylent-only diet for an extended battery period.

Way past my bedtime. Hope this post is actually coherent. :slight_smile: