Not sure about salt intake vs. weight loss, but The National Academy of
Sciences recently recommended increasing the amount of potassium in our
diets, to help regulate blood pressure. Most of the "salt substitutes" are
made from potassium chloride, which can provide a significant amount of
potassium, and I find they taste good on food.  From the NAS report:

"To lower blood pressure, blunt the effects of salt, and reduce the risk of
kidney stones and bone loss, adults should consume 4.7 grams of potassium
per day. However, most American women 31 to 50 years old consume no more
than half of the recommended amount of potassium, and men's intake is only
moderately higher."

The press release for this report is here:

http://www4.nationalacademies.org/news.nsf/isbn/0309091691?OpenDocument

Doesn't make sense to me either.  Salt is inorganic so it has no carbs,
fat or protein.  Salt is present in the blood and the human body is
evolved to eject vast quantities of excess salt so it has no effect on
building muscle, withdrawing fat, etc.