Came across this just now.
Tully (2018)
https://www.imdb.com/title/tt5610554/
Charlize Theron gained 50 lbs for this film that even her own youngest child thought she was pregnant.
She did so by eating in-and-out burgers and junk food and macaroni and cheese at 2 am.
It took her over 1 1/2 years to shed the 50 lbs.
She better get her Oscar acceptance speech for Best Actress ready.
https://www.youtube.com/watch?v=e5D3O4yCmCg