writes: Salty diet makes you hungry, not thirsty. Science Daily reports: "In a study carried out during a simulated mission to Mars, an international group of scientists has found exactly the opposite to be true. 'Cosmonauts' who ate more salt retained more water, weren't as thirsty, and needed more energy." So if you don't want to gain weight on your trip to Mars, don't eat salty chips. If you don't want to gain weight at home, maybe you should stay away from them as well.
From the report: "The studies were carried out by Natalia Rakova (MD, PhD) of the Charite
and MDC and her colleagues. The subjects were two groups of 10 male volunteers sealed into a mock spaceship for two simulated flights to Mars. The first group was examined for 105 days; the second over 205 days. They had identical diets except that over periods lasting several weeks, they were given three different levels of salt in their food. The results confirmed that eating more salt led to a higher salt content in urine -- no surprise there. Nor was there any surprise in a correlation between amounts of salt and overall quantity of urine. But the increase wasn't due to more drinking -- in fact, a salty diet caused the subjects to drink less. Salt was triggering a mechanism to conserve water in the kidneys."