Thing is most people consume too much sodium and throw the potassium/sodium balance off. This can cause water to remain outside the muscles under the skin. So a restriction, not a total elimination of sodium can help some people. This is a pretty good article on potassium, sodium and water.
"A conversation about the influence of water and carbs on appearance is not quite complete without talking about sodium and potassium. Sodium is responsible for regulating extracellular water while potassium regulates intracellular water. A common mistake among competitors, aside from dropping water, is dropping sodium and increasing potassium in an effort to draw more water into the muscles while pulling subcutaneous water out. Although this procedure of dropping sodium and increasing potassium in conjunction with a decrease in water may seem logical considering the role these ions play, doing so is anything but. These ions must be properly balanced in order for fluid dynamics inside the body to remain stable. Read that statement one more time. They must be properly balanced!
Under normal conditions when sodium and potassium are balanced and water is in constant supply, most of the water is held inside the muscle cells while all excess water gets excreted. What makes eliminating sodium to further eliminate subcutaneous water wrong is that when sodium levels drop below normal the body releases the hormone Aldosterone. Aldosterone causes the body to reabsorb and prevent the excretion of sodium. The result of this is the retention of water outside the cells. Hence, what you are trying to do to eliminate subcutaneous water is precisely what causes you to retain it. The lower and longer sodium is dropped the greater the release of Aldosterone and the worse the situation develops. To compound the problem even further—if you didn’t think it could get worse—increasing potassium way above normal levels or at least way above sodium will also cause a release of Aldosterone.
The key to achieving that dry, shredded look, while keeping the muscles full, is to maintain “normal” sodium and potassium levels. This means that your sodium intake should be in the range of 1‐3 grams and potassium should be 1.5‐2 grams.
The Synergistic Effect of Water, Carbs, Sodium & Potassium on Appearance
For all the complexities and nuances associated with the elements mentioned throughout"
By Michael Lipowski, CFC