Mighty.Sun.Tzu
Hi Mouseclick,
Some pertinent exerps about sodium and it's relationship to water in our bodies out of the wikipedia arcicle.
"Thus, when a powerful diuretic drug is given which causes the kidneys to excrete sodium, the effect is accompanied by an excretion of body water (water loss accompanies sodium loss)."
Since we excrete sodium in a fast, it follows that we excrete body water as well.
Nobody here really believes we are burning 20
pounds of fat on a 7 day water fast, right?
"It (sodium) is also a component of many minerals, and it is an essential element for animal life."
Sodium serves a vital purpose within our bodies.
"The human requirement for sodium in the diet is about 500 mg per day, which is typically less than a tenth as much as many diets "seasoned to taste." Most people consume far more sodium than is physiologically needed."
"... However, low sodium intake may lead to sodium deficiency."
Thus there are healthy levels of sodium and the possibility for having too much or too little in our diets. I am not certain about this (will have to research it further or hear from Chrisb1), but i believe with a fair amount of intuitive confidence as well as considerable experience with fasting and weight log keeping, that in a fast, we dip to below normal/optimal levels of sodium (and our accompanying water level dips to below normal)... and when we return to normal eating, we return to normal levels of sodium and water content in our bodies. We don't have to eat "too much" sodium to regain our healthy water levels.
... and if we return to eating which includes too much sodium, we will gain back our normal water levels and then be saddled with "excess water retention" on top of it.