Did you know that many astronauts crave spicy foods once in space? Scientists believe that this is because fluids shift from the lower to the upper parts of the body because of weightlessness. This creates nasal congestion. Because odor is essential to the sense of taste, a decrease in the perception of flavors would occur, hence a craving for more powerful tasting foods. Astronauts claim that their taste preferences sometimes completely shift once in space, then return to normal.