They always eat sealed packages so their silverware also includes a little pair of scissors to cut open the packet. The meal itself consists of foods that are specially treated to preserve them and prevent bacteria from growing on them. Also, astronauts have to keep in mind that eating healthy " is a little different in space. For example. since they are in a zero-gravity environment, their bones become weaker, so they make sure to eat a calcium-rich diet and take vitamins. Even more interesting is the fact that some foods actually are dangerous in space. such as bread and other foods that make crumbs. An astronaut could get sick from inhaling bread crumbs that are floating around the cabin . Hot food is also dangerous because if it floats away and touches an astronaut, it could burn him or her.