I decided that the chapter on how to potty train an astronaut was probably not the best one to quote from for those of you about to eat dinner, but this bit about researching what foodstuffs to send into space really made me laugh.
"Three times a day, experimental meals would be left by dieticians inside a pretend airlock. Over the years, recruits survived on all manner of processed and regimented aerospace foods: cubes, rods, slurries, bars, powders, and "rehydratables". Dieticians weighed, measured, and analyzed what went in, and they did the same with what came back out. "Stool samples were ...homogenized, freeze-dried and analyzed in duplicate," wrote First Lieutenant Keith Smith in a nutritional evaluation of an aerospace diet that included beef stew and chocolate pudding. You had to hope that Lieutenant Smith kept his containers straight."