You lose mass by exhalation of CO2, not defecation. Since you inhale O2 and exhale CO2, you don't need to inhale more than you exhale (a mathematical impossibil

You lose mass by exhalation of CO2, not defecation. Since you inhale O2 and exhale CO2, you don't need to inhale more than you exhale (a mathematical impossibility anyway, of course) to lose weight.