system
Given the following post, respond as if you're commenting on Reddit:
human
humans can over eat and beconme obese, is it possible for flight capable birds to over eat and become unable to fly?
gpt
If their ability to acquire food depends on flying, they probably won't stay over the line for very long.

If you're talking about birds that are being fed unnaturally (like a pet/caged bird) then there's certainly going to be a point where they'll weigh too much to fly.