Ate Too Much Salty Chips? Here's Why You're Hungry Now

We've always known that eating salty foods increases thirst. But this knowledge, it turns out, is more of a superstition. A study conducted by the German Aerospace Center in collaboration with the Max Delbrück Center for Molecular Medicine and Vanderbilt University found that consuming salty foods actually retains water in the body and reduces thirst.

It is unclear why, but until now, no long-term study has examined the connection between the amount of salt in a person's diet and their drinking habits. Scientists simply knew that a person consuming more salt produces more urine – assuming that the excess fluid excretions are the result of increased drinking. The German study, however, found completely different facts.

The research subjects were two groups of male volunteers who were locked in a simulated spacecraft and underwent a Mars flight simulation. The first group was tested for 105 days, and the second group for 205 days. Both groups were on the exact same diet, but received varying amounts of salt in their food.

The results confirmed that indeed those who ate more salt produced more urine, and it was saltier. But the difference was not due to different drinking quantities: in fact, those who ate saltier food, drank less. Salt consumption triggered the kidneys to activate a mechanism that retains water in the body. Until now, researchers believed that the substances in salt 'stick' to water molecules and carry them out in the urine, but this study showed something entirely different: the salt remains in the urine, while the water 'returns' to the kidneys and the body.

How does this happen? Experiments conducted on mice hinted that a substance called urea is responsible for this occurrence: as salt intake increases, it acts as a counterforce to the attraction of salt and retains water in the body. However, producing urea requires a lot of energy from the body, which is why both the participants and the mice that consumed more salt – were much hungrier.

What do these discoveries mean for you? Next time you polish off a bag of salty chips, notice that you don't feel the need to drink a liter of water afterward. But also notice how soon you'll begin to feel really...hungry.