Are there any incidences where I should up my salt intake- e.g. if I have been physically working hard on a hot day, or when abroad in a hot climate?
No, if you eat little or no salt then there is no salt in the sweat.
No s#!t, Sherlock.
The salt concentration in sweat is controlled in the exactly the same way as the urine. The body will adjust and hold onto any salt if a lot is being lost in the sweat.
The converse is also true: if you consume more salt, then you excrete more salt.
Call me paranoid if you like, but I’m finding it difficult imagining that these people do not have an ulterior motive. We’ve been eating salt for years, and some people eat quite a bit more salt than us Brits; so how come it’s only started affecting us now?
Disclaimer: Speaking as someone who once came close to dying of acute hyponatraemia, and as someone who no longer enjoys a certain high street bakery chain’s pasties because they do not contain enough salt to bring out any flavour, I do have a bit of a vested interest in this.