4 ms·

Does all the CO2 from food get exhaled or does some get passed with stool?

• ben_w 5y ago
  CO2 is a gas, stool isn’t. More specifically, the CO2 has to get out of your blood to make way for the next load of oxygen, and that happens in your lungs not via your digestive tract.
  • ivalm 5y ago
    He slightly mis-wrote, he meant percentage of carbon from food that gets converted to CO2 and then exhaled. Not all of food carbon becomes CO2 therefore you don’t need exactly equivalent biomass growth to offset food consumption.
  • LargoLasskhyfv 5y ago
    But stool is gassing out too. Sometimes very noticably so...
    • ben_w 5y ago
      Farts are not your breath. And if any significant fraction of the carbon in your stool converted into CO2 (which is odourless), released continuously would be bad enough (not as bad as breathing through your backside but much worse than any normal farting), and doing so all at once would be dangerously explosive — in the “you need emergency hospital treatment for a ruptured intestine” sense rather than a the slapstick comedy sense.
      • LargoLasskhyfv 5y ago
        Errm...I meant in the 'externalized' already 'dumped' phase.
• saalweachter 5y ago
  I think it was around 80% of the carbon in food that ended up exhaled the last time I did the math.