The 27-year-old actress works hard to maintain a slim physique, particularly for the tight-fitting catsuits she has to wear in her role as Black Widow in the forthcoming `Avengers` movie, but does not enjoy the amount of time she has to spend in the gym so as not to worry too much about what she eats.
She said: "I hate having to be so disciplined, and I don`t like to be told to do anything. Not that everyone`s telling me what to do - they just expect me to arrive onset and not be fat.
"I exercise and eat well. I do it so I can indulge every now and then. I can have half a bottle of wine and not sit around thinking, oh my God, all those calories! However, when you`re working and getting up at 4am to train for three hours every day, drinking isn`t what you necessarily want to do. The discipline it takes to keep to that schedule sucks."
As well as disliking her intense exercise regime, Scarlett is not a fan of having to have red hair for the role because it is such a struggle to maintain.
She added in an interview with Australia`s Daily Telegraph newspaper: "I`m done with red hair. It`s so much upkeep. I don`t want to be in the salon any more. I hate sitting there, the smell, the cape."