system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What happens to extra blood vessels when someone loses a substantial amount of weight?
gpt
In the short term, nothing at all. Only after a long time of disuse will there be remodeling. Think of the cells and blood vessels like houses. When somebody moves out of a house, it's not immediately torn down. It's kept in case you need to fill it again, with people, or with fat deposits. Only after a long time with no one using or caring for the house does it get bad enough to be torn down, and all the internal piping and wiring with it. Same with the empty fat cells. Your body invested a large amount of resources and energy making those cells and vessels, it's going to keep them until it's absolutely sure you don't need them anymore. Incidentally, this is also why weight loss requires a long term change of lifestyle. If you lose fifteen pounds over a couple months, then go back to normal, your body will just fill back up the old infrastructure it had, storing up just in case.