One moment, please <a href=" http://janematthewsdesign.com/cymbalta-90-mg-daily.pptx#polish ">cymbalta for nerve pain relief</a> The nutritional requirements of astronauts are similar to earth dwellers. Both groups eat 2,700 calories a day, on average, because astronauts expend as much energy trying not to float into things as we spend walking on the ground. Astronauts request a low-fiber diet, Hunter said, because pooping in space is complicated and crews like to keep it to a minimum. Calcium levels have to be high enough to maintain bone density, but not so high that the calcium passes through the astronauts and clogs the spacecraft&#39;s urine recycling system. Iron is kept low because changes to red blood cells during the first few days of a mission can send iron levels dangerously high.