There's a series of Japanese roleplaying games called "Far East of Eden" in the west or "Tengai Makyou" in Japan. In the game "Tengai Makyou: Daishi no Mokushiroku - The Apocalypse IV" there's an extremely well done weight gain sequence that I think is now more popular in the West compared to the game itself. (Especially since the game was never localized).
https://youtu.be/I62tBctqKD4
Unfortunately this is the looped version so the full context for the TF isn't available. But it's a really great sequence and one I really love.