1. Christian Bale gained 43 pounds for his role in American Hustle.
2. Christian Bale also lost 63 pounds for his role in The Machinist. His diet consisted of apples, coffee, and cigarettes.
3. Natalie Portman shaved her head for her role in V for Vendetta.
4. Natalie Portman also spent eight hours a day training as a ballet dancer for her role in Black Swan.
5. Timothée Chalamet learned how to speak fluent Italian for his role in Call Me By Your Name.
6. Bryan Cranston actually learned how to cook crystal meth for his role in Breaking Bad.
7. Danai Gurira underwent intense sword training for her role in The Walking Dead.
8. Adrien Brody lived off of the bare minimum — two suitcases of minimums, to be exact — to prepare for his role in The Pianist.
9. Joaquin Phoenix lost 52 pounds for his role in Joker. He said losing that much weight made him "go mad."
10. Halle Berry didn't shower for two weeks to get into character — a drug-addicted prostitute — for her role in Jungle Fever.
11. Margot Robbie practiced ice skating for five months to prepare for her role in I, Tonya.
12. Robert Pattinson lived in the isolated apartment of the character he played — even going as far as to keep the curtains closed and not change the sheets — to prepare for his role in Good Time.
13. Jamie Foxx wore prosthetic eyelids to simulate blindness while filming Ray.
14. Robert De Niro worked 12-hour cabbie shifts for a month to prepare for his role in Taxi Driver.
15. Charlize Theron shaved her eyebrows and fried her hair to prepare for her role as serial killer Aileen Wuornos in Monster.
16. Anne Hathaway lost 25 pounds and shaved her head for her role in Les Miserables.
17. Rooney Mara got actual piercings — in her ears, lip, brow, nose, and nipples — to prepare for her role in Girl with the Dragon Tattoo.
18. Shia LaBeouf joined the US National Guard to prepare for his role in Fury.
19. Nicholas Cage had four of his own teeth pulled to better portray his character in Birdy.
20. Hilary Swank bound her chest to prepare for her role in Boys Don't Cry.
21. Jamie Dornan once stalked a woman when they exited the subway to prepare for his role in The Fall.
22. Chris Hemsworth went on a 500-calorie-a-day diet to prepare for his role in In the Heart of the Sea.
23. Finally, Daniel Day Lewis — known for his method acting — lived without electricity or running water while filming The Crucible.
