Semi-realistic Regeneration and corresponding Increased Consumption

[vicky_molokh]

Greetings, all!

Due to closer scrutiny towards certain mutations and biomods, I'm interested in making the Regular Regeneration (1HP/hour) biomod at least semi-realistic in my campaign. That's an approximately 50-fold increase in natural healing capabilities compared to an average human (24HP per day instead of ½HP per day). Now, a person eats 3 GURPS meals per day, but most of that isn't spent on healing HP. So the question becomes: assuming that the process of regeneration has an impressively high coefficient of efficiency, just how much extra food would be required when the organism kicks into such a high gear? I'm assuming at least some of the damaged-but-retained biological material could be recycled by the nanites/weird-phagocite-and-mobile-stem-based-repair-cell-system, though I'm not sure at which point the semi-realistic turns into outright physics-defying. But even while building materials can be somewhat recycled, energy needs to come from somewhere - just how energy-intensive would be a 50-fold boost of healing, in terms of extra food consumption? Finally, how much of a buffer can be retained by using additional internal storage of nutrients/slow energy, purely through improvements to the biochemistry of storage (i.e. without resorting to making the person fat)?

Thanks in advance!

[GodBeastX]

I'm reminded of a kid who was born with the disease that he constantly generates skin cells. I imagine regeneration of this magnitude would be similar in idea. The person in question has to eat thousands (It was an absurd amount... something like 8,000 to 12,000?) of calories in protein a day or die.

[Bruno]

Originally Posted by vicky_molokh

Due to closer scrutiny towards certain mutations and biomods, I'm interested in making the Regular Regeneration (1HP/hour) biomod at least semi-realistic in my campaign.

I always like looking at this sort of thing. It's an interesting mental exercise.

Originally Posted by vicky_molokh

...just how much extra food would be required when the organism kicks into such a high gear? I'm assuming at least some of the damaged-but-retained biological material could be recycled by the nanites/weird-phagocite-and-mobile-stem-based-repair-cell-system, though I'm not sure at which point the semi-realistic turns into outright physics-defying.

Recycling material almost certainly involves some scary waste products - diseases like malaria and ebola rapidly dismantle cells, which produces a lot of chemical byproducts. Doing it quickly overwhelms the liver and kidneys (which both diseases make worse by directly attacking of course, but we'll assume the magic regeneration thingies have the sense not to do).

So you'd probably have a requisite of a boosted liver and kidneys if you want to go this route.

You also need to reclaim fluids that have been leaked into places they shouldn't go. That can be tricky, you'll be fighting the bodies natural inclination to swelling. There's also the cell-filled fluids and tissues that are flat out not in your body any more so there's limitations.

Originally Posted by vicky_molokh

But even while building materials can be somewhat recycled, energy needs to come from somewhere - just how energy-intensive would be a 50-fold boost of healing, in terms of extra food consumption?

Faster than the digestive tract can help with if you're hoping to get it by eating after the injury, I suspect.

Originally Posted by vicky_molokh

Finally, how much of a buffer can be retained by using additional internal storage of nutrients/slow energy, purely through improvements to the biochemistry of storage (i.e. without resorting to making the person fat)?

If you're not storing it as fat, then you must be storing it as sugars, which is pretty unheard of for mammals (tetrapods in general I think) but I don't see why you couldn't do it in genetic engineering or with nanites or with a sugar-water fuel tank or whatever. But you need more than just energy - you need all the nutrients, because that's what people are made of and you'll need to rebuild things.

If it's "only" a hole poked in you or a cut, then you need to build the scaffolding for new tissue, new tissue, and new blood volume (where's the water coming from?). We'll handwave how the nanites align your tissues correctly and keep them that way while healing without you being strapped in place.

If you've had major tissue damage (fire, chemical burns, the kinds of trauma that takes flesh right off you even if it's not a GURPS amputation that you need Regrowth for) then you need to magic that material out of somewhere. And the logical place for that is your other bones and muscles.

The most obvious way to store the reserves is extra-heavy bones and excess "unsupported" muscle mass that is dismantled by the nanites and relocated to where it's needed.

[Anthony]

Originally Posted by vicky_molokh

So the question becomes: assuming that the process of regeneration has an impressively high coefficient of efficiency, just how much extra food would be required when the organism kicks into such a high gear?

A lot depends on the amount of reclamation of damaged tissue vs growth of new tissue. If you're simply growing new tissue, best-case for things like chicken farming is 2-3 pounds of food per pound of tissue, and bear in mind that the slaughtered chicken is something like 70% water while the feed is mostly dry. However, the amount of actually destroyed tissue in most injuries is fairly small, so if you can just do a good job of knitting damaged tissue back together you don't really need to create much new tissue (and different damage types would be different. Burning and corrosive damage should be relatively hard to regenerate, piercing and impaling relatively easy).

[Celti]

Since After The End introduced Long-Term Fatigue (which I've been using for a lot more than just AtE games), I've been treating (semi-)realistic Regeneration as costing 1 LFP per HP, which very handily abstracts away levels of Increased Consumption, etc. into “your body is expending lots of resources on healing, so you're tired and need to rest, eat, and drink a lot to make up for it”.

Both I and my players love the reduction in bookkeeping, etc. that this brings on while maintaining verisimilitude.

[(E)]

I have read somewhere that 90% of a person's healing happens when they are asleep. (HGH and other useful hormone levels rise and temperature changes etc). Perhaps while healing/regenerating there are other changes in a person's physical and mental performance.

[starslayer]

But that's the thing about regeneration- any sort of fast regeneration is realistically NOT going to involve a lot of cellular generation, but instead focus on radically increased capability to 'glue' back together. Perhaps blood that contains some sort of very reactive chemical that upon exposure to nitrogen causes cells to loosen there bonds so that they will 'glue' to any other cells they encounter

A regenerator that simply had a more flexible and distributed cell structure (IE- more like an amalgam of independent cells that an interdependent network) could sustain many times over 'lethal' from a cutting weapon damage, and as long as the flesh has enough time to press against itself happily sew back together and cost essentially nothing except a series of lurid scars from the imperfect joining.

What would cost a lot of energy is constantly producing 'glue blood' (as anything that is reactive is by definition energy intensive), and the overhead for building (and maintaining) a multiply-redundant distribution structure (So that simply glueing flesh back together leaves it functional instead of numb and dying in the event of a nerve cut or vein/artery damage).


So a 'realistic' regenerator would have increased consumption, but no special fatigue cost for the act of regenerating (at least beyond the fatigue cost you would apply to a human to have suffered identical wounds).

[Anthony]

Originally Posted by starslayer

So a 'realistic' regenerator would have increased consumption, but no special fatigue cost for the act of regenerating (at least beyond the fatigue cost you would apply to a human to have suffered identical wounds).

Well, it could easily have limited reserves of supercoagulin or whatever you choose to call your glue blood, which means the regeneration shuts off after a while and healing rate drops to normal (or some elevated or depressed normal, depending on the way the special blood is generated).

[Anaraxes]

Real-world medical recommendations seem to be 30-35 Calories (kcal) per kg of body weight, sometimes more. That number also assumes that you're idle in your hospital bed, so the usual maintenance requirement is reduced. So, it's something like a 10% increase over normal maintenance, or more.

If we take a 10% increase and assume it's linear with the 50-fold increase in healing, that's 5x food to fuel the Regeneration, or 6x with the normal food intake. Though the pentaphilic number is appealing :)

[Flyndaran]

Originally Posted by GodBeastX

I'm reminded of a kid who was born with the disease that he constantly generates skin cells. I imagine regeneration of this magnitude would be similar in idea. The person in question has to eat thousands (It was an absurd amount... something like 8,000 to 12,000?) of calories in protein a day or die.

I think that's a bit of a misdirection as he obviously was not using all that protein for fuel. So the caloric density means little as he used it for building materials.
No normal sized human could breathe fast enough 24/7 to oxidize 12k Calories worth of food a day. Just imagine breathing five times as fast as you do normally but constantly.
I remember the poor guy you're probably thinking of. Feeding tube during the night to ingest the sheer volumes of pure protein slurry needed. Even the dual facts of his constantly red cracked sloughing skin and that he swam in the salty ocean made me cringe.