Mark, Bletchley asked:
Do astronauts change their diet before they head off into space?
In the early days NASA did worry about astronauts’ diets and going up into space for various reasons. One is that if you have gut flora or bacteria that break foods down into gas: if you eat foods that they like breaking down and turning into gas, then there’s a worry that you could end up making a lot of gas and that could be quite unpleasant in your spacesuit. That was the theory, so diets were selected to be what’s called, ‘low residue,’ and fairly stomach-kind.