2. Jared Leto
Before he was our new favorite villain as the Joker, Jared Leto had other amazing works. One of them was in the movie Chapter 27 where he played the role of John Lennon’s killer. To prepare for this movie, Leto went on a weight gain routine. He gained a significant amount of weight and the sudden gain left him with a severe gout-like foot pain. Leto has gone on record to admit that he had to force feed himself to gain so much weight and that he hated every bit of it. He even mentioned how he would never gain weight for a movie role. Who knew eating so much was so bad?