Charlize Theron has stated that she no longer intends to drastically change her weight in order to play the character.

Oscar-winning actress Charlize Theron has said she’s no longer going to drastically change her weight to play a role in movies or on television.
The South African star lost without problems 15 kg weight for a monster but it was even more exhausting when he had to try his hand again in Jason Reitman’s film Tully:“I will never do a movie again where I say, ‘Yes, I’m going to put on 40 pounds.’ Three meals and I’m back to my normal weight. Then I did it at 43 for Tully and myself. I remember a year when I was trying to lose weight, called my doctor and said, “I think I’m dying because I can’t lose weight,” and he said, “Calm down, you are over 40. Calm down. Your metabolism is not what it used to be.” Nobody wants to hear about it.”.
A change that Theron also noticed while filming action movies:“What pisses me off is that now I’m doing action movies and if I get injured it takes a lot longer than it did when I was 20. an old body that I can just throw against a wall and not even get sick the next day. Now if I don’t train for three days and go back to the gym, I can’t walk. I can’t sit on the toilet. all very real moments.”.