system
Given the following post, respond as if you're commenting on Reddit:
human
Do humans permanently retain some portion of the water they consume or is all of the consumed water eventually lost/replaced?
gpt
The other thing to consider is that water molecules are constantly being created and destroyed by chemistry. Proteins and other large molecules are hydrolysed (cut by water) where the H2O becomes an OH that leaves on one molecule and the H leaves on another. Similarly, building up new versions of proteins, etc creates 'new' water molecules that may have come from the atoms of things you ate, or oxygen that you breathe in.