system
Given the following post, respond as if you're commenting on Reddit:
human
When you "burn fat" how exactly do you loose mass?

Do we sweat more, poo more, per more?
gpt
the main source of sustainable weight loss is through breathing. You can of course lose mass by sweating and peeing, but that is not sustainable as most of that loss is water which needs to be replaced for proper function of organs. Weight loss (specifically of fat) follows the same formula as burning gasoline:

fat molecules CnHmO6 (rough chemical formula of a component of fat) are oxidized by O2 to produce CO2 and H2O. The CO2 is expelled through breath, the H2O is, as mentioned before, added to the overall water balance of the organism. Since the majority of the mass of the fat molecule is stored in the Carbon (roughly 4-6 times more massive than hydrogen on a weighted average in fat molecules), the majority of the mass is lost through production and exhalation of CO2.