Backpacking/Hyponatremia Question

The expert consensus statement is not primarily aimed at “normal circumstances” but at circumstances of prolonged exercise in heat, such hot weather Ironman events, ultamarathons, or R2R type activities. They are aware however that less significant events have also had EAH occur as the hydrate early and often with no regard to thirst became such entrenched bro-science.

So per that expert consensus statement if someone is very very thirsty because they have been sweating lots and drinking a lot to satisfy that thirst but not exceeding it, they are at low risk of either hyponatremia or significant dehydration, whether they are eating much or not. Of course one should still eat during an R2R and some salty foods like pretzels, nuts, and beef jerky (carbs and protein) as snacks seem to me to make for some reasonable sense. And nothing wrong with sports drinks. Just nothing magical or all that scientific either. Drinking sports drinks is not a replacement for the single most important item - listening to your thirst both as the cue to drink and to its satisfaction as the cue to stop drinking.

If someone is very very thirsty and so drinking a lot and not eating enough to satisfy hunger (as might well happen when backpacking the Grand Canyon), then they should drink when thirsty and stop drinking when not. That is the most effective and safest response to worrying about salt/potassium and about hydration.

Some how, i do not think not knowing when to drink was the cause.
It might have more to do with the fact that back then, when shopping for meat, the meat had ideas of it’s own

Or it may have more to do with being able to more effectively treat people who are ill and keep people who are healthy from becoming ill. …Or, most likely, it’s a mix of all of the above.

And surviving infancy and then early childhood (huge numbers each, including by infanticide). Not dying a violent death as a teen to young adult male and not dying giving birth or soon after as a teen to young adult female. The average life expectancy was in general actually much lower than 30 to 40 because so many died so young but if someone got to their late twenties living to 50s to late 60s was not uncommon.