Nonsense. Salt (sodium) is essential. But it works in concert with potassium. For years I went low sodium with poor results. I didn't realize I was low on potassium.
I don't retain water anymore. Zilch. And I don't scrimp on salt.
My health today is dramatically better. I did it w/o having to resort to any prescription medications.
I'm 64.
Low carbs - medium protein - high fat.
It works.