system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Where does weight actually go when one is losing it? How can I go to sleep weighing 202 and wake up weighing 199?

So yeah... Always wondered this. During the process of losing weight, how does it actually leave your body? Does exercise convert it to waste and then you just get rid of it that way? If so, when losing weight, does one have to go to the bathroom a LOT more? How does it just magically disappear? It's always perplexed me.
gpt
>how does it actually leave your body?

Primarily through your breath.  You breath in (some) O2, and breathe out (some) CO2.  The extra carbon in there comes from your body "burning" sugars, converting sugar + O2 into H2O and CO2, which you breathe/sweat/urinate out, as appropriate.

Fun fact, plants use a similar process in reverse.  That is, the solid bulk of trees is made up (mostly) from carbon in the air.  Thus trees grow from material in the air, not material in the ground as many people seem to think.