[nabla9]

You risk heart attack even if you are in water only diet (without salts and potassium) for longer periods of time (several weeks).

[sph]

Stupid question, but if stuck in the desert you can suck on some rock to recoup some lost minerals, no?

I guess like any deer we'd immediately recognise (and love) the taste of rock salt

[darby_nine]

I've got to imagine this would mess with our ability to cool ourselves even if it gave us more water retention.

[77pt77]

That basically only happens if you do a water fast with distilled water.

Regular mineral water will avoid that.

[Enginerrrd]

Uhmm, No... no it will not. That is dangerously incorrect.

Mineral water may have a small amount of trace minerals, but it has basically zero electrolytes at relevant physiologic concentrations. Functionally, there'd be almost no difference between distilled and mineral water fasting with respect to electrolyte management.

Imbalances in sodium, potassium, magnesium and calcium can get VERY serious very quickly. Mineral water does not really have relevant concentrations of those.

I think you're conflating the idea that distilled water isn't particularly good for you since it starts leaching out the trace minerals from parts of your body, with the entire concept of electrolyte management. These are VERY different things, occurring with VERY different relevant concentrations... like at least 1-2 orders of magnitude.

[cycomanic]

> Mineral water may have a small amount of trace minerals, but it has basically zero electrolytes at relevant physiologic concentrations. Functionally, there'd be almost no difference between distilled and mineral water fasting with respect to electrolyte management.

This might be correct for what is considered mineralwater in the US (I honestly don't know), but 1l of typical sparkling mineralwater in Germany has about a third of your daily magnesium and calcium recommended amounts (as well as relevant amounts of a view others). https://www.gerolsteiner.de/wissensquellen/wasserwissen/mine...

And there are waters with even higher concentrations.

[Alupis]

Just a note, most mineral waters are not entirely natural, and contain added minerals and electrolytes. The water coming out of your tap, for instance, does not contain anywhere near the levels of minerals and electrolytes as a bottled mineral water product.

The GGP mentioned "regular mineral water" - but most of us (at least in the US) do not purchase bottled mineral water to drink on a day-to-day basis. Most of our water consumption, in one way or another, comes out of the tap.

[f1shy]

That is 1/3 of the minerals you are supposed to get from water! It is recommended 6g of Na per day, which you will not get just from water.

[lukan]

Where do you get that from? No, it is the amount of minerals you are recommended to get during one day, no matter the source.

And for Na the recommended ammount is 1.5 g (from D-A-CH)

But in the example linked above, 1 l of the water gives 118 mg of Na, so 13 l of water would be needed to get the required Na amount. Not practical, but most mineral waters actually come rather with an artifically reduced amount of Na. Natural sources probably have higher values.

But in

[f1shy]

The number comes from the NEJM. For low Na diet, 6g Na per day. I do not know any medical association called D-A-CH or any guidelines (Leitlinien or Richtlinien) which are universal for those countries; can you cite better? And 13l of water is not unpractical but poisonous. You just die.