If you remember a specific title or creator, I can help narrow it down further.
Just to clarify: there is no single official game with that exact title. Instead, "weight gain game" is a common tag used by indie developers for interactive fiction, RPGs, and visual novels focused on expansion, inflation, or transformation themes. weight gain game on itch.io
It sounds like you're looking for the Weight Gain Game hosted on . If you remember a specific title or creator,