As you all know, astronauts spend a lot of time in space and there are no shops where they can buy food. Your only option is to take everything from Earth.
All food must be packaged properly for it keep whitout any refrigerator, for a long time. In addition, food should be easy to prepare and eat, as astronauts always have a lot of work, so they can't spend much time eating.
Evolution of food in space:
The first meals in the space were very "strange", it were basically tubes of aluminum with folders or small cubes of food. There have always been many problems when thinking about improving food in space, because much care is needed. For example, a simple crumb of bread can cause many problems for the spacecraft or even for astronauts.
Over time, the food was improving, including the food cubes, which began to be made with a gelatin on the outside so the crumbs did not disintegrate. Then the packaging improved, and consequently the food was better.
It was at the Apollo mission that hot water existed for the first time in space, making it possible to rehydrate the food, making it tastier. Apollo astronauts were also the first to eat in the "spoon bowl", which is a plastic recipient with an opening through which they fed.
