Ever finished a bucket of popcorn at the movies and thought “you know, that really hit the spot”, or opened a bag of chips, had a few and put it away because you felt like you’ve had enough? I’m betting that never happened to you. In fact, I’m betting you had to actively fight your desire to eat through the entire bag of snacks in one sitting.
Well, apparently, there’s a science to this effect, and it boils down to one prime ingredient common to all foods that turn us into a bottomless pit of hunger: salt.
We all know that salt makes us thirsty because it’s a drying agent that absorbs humidity, right? Wrong. In a study conducted by a team of American and German scientists and published in 2017, they found that high salt intake made people urinate more and drink less water while making them substantially hungrier.
The team tested a group of 10 Russian cosmonauts who took part in intense flight simulations, where the would-be spacefarers were in a controlled and secluded environment, making it the ideal setting for such research.
The cosmonauts were given different doses of salt in their food with no other changes to diet over the testing period. What seemed to happen was that an increase in salt triggered a water-conservation mechanism in their bodies that accounted for their decreased sense of thirst.
Also, as the salt levels were higher, the cosmonauts reported feeling hungrier, despite the calorie content of their food remaining the same. Dr. Jens Titze, one of the study’s authors, postulates that the body exerts energy in order to conserve water, causing an increase in hunger as the body needs more calories to burn to sustain the conservation effort.
In a separate study, the team of researchers attempted to test some of their hypotheses on mice. They found that a salt-rich diet caused the mice to secrete more urea in their kidneys. Urea (one of the main components of urine, after which it is named) was thought to be a waste product, but this research proved it had a far more important function. The urea in the mice appeared to protect the water from the absorbing elements in the salt but synthesizing this much urea was draining on the mice, causing them to eat more. Moreover, they found that in salt-fed mice, the body was using up proteins in the muscle system in order to induce the creation of surplus urea, causing loss of muscle mass.
All of this comes on top of the more widely-known negative effects salt has on blood pressure. As in most things, people are not encouraged to fully eliminate salt from their diet, as it serves several crucial functions in our body. Rather, you should use it in moderation, and abstain from overly-salty snacks as much as possible.
Watch Dr. Titze explain the study and their incredible findings: