If matter can only change form through physical and chemical changes, where does all the matter we get rid of when losing weight end up in?

Question

If matter can only change form through physical and chemical changes, where does all the matter we get rid of when losing weight end up in?

In: 65

Answer 1

Not sure if it’s truly ELI5 but this has to be linked:

The mathematics of weight loss. Some formulas, experiments etc that answer your question.