If you haven’t seen Gone Girl, then do yourself a favour and read the book and then go out and watch it (just maybe not with your significant other – men have a reason to be scared of the main character, played by the incomparable Rosamund Pike, in this movie). Rosamund actually had to put on and take off weight [13 pounds on an off her 5’8 1/2, 130 pound frame body] 3 times to play the character at different stages of the movie.  As you know, yo-yo dieting is terrible for your body, so in that sense Rosamund really suffered for her craft. Rosamund also did incredible things to transform her voice at various stages of the movie. I highly recommend reading the Variety article cited below to gain a further understanding of how she did that.
Rosamund has said, “I had to be slimmer in L.A. and heavier in the Ozarks, and then heavier and slimmer in the studio, so I had to do it three times over. They scheduled around it, so I had two weeks each time for each fluctuation. It was quite intense. It was like turning your body into a chemistry lab. I couldn’t escape it, the weight-loss period. I took time out to get a pedicure, and Extreme Weight Loss! was on the TV. I was like, “I can’t get away from it!”  Though she can laugh about it now, having to lose weight that fast is most women’s idea of a nightmare. So how did she do it?
Rosamund Pike’s Gone Girl Exercise Routine
Rosamund has said, “I trained with a boxer, [welterweight Holly Lawson]. Anyone who is going to go into the ring will usually rest over their fighting weight, and then lean out to go into the ring. So they’re very conversant in being one weight, and then having to drop in a confined period of time. So it made perfect sense, right? Because of their ability. To a certain extent, my body cooperated, but I don’t know how good it is for you.”  Rosamund has called the weight loss/gain that she did for this movie “schizophrenic,”  while for many people a fluctuating BMI is a way of life that they do not feel like they have control over. She boxed for 4 hours a day in order to lose the weight that she had put on for the Ozarks scenes and was regularly running 5 miles in 42 minutes. 
Rosamund Pike’s Gone Girl Diet
“I was eating crap, eating well, eating crap, eating well,” Rosamund told Variety “Bulking up and leaning out.”  She ate a lot of hamburgers and milkshakes to achieve the Ozarks look and then a lot of lean protein and greens to achieve the Fantastic Amy look. 
What really impresses me about Rosamund Pike is that she could have asked David Fincher, her director, to add padding to her body and face to create the illusion of weight loss, but she decided that it would be more authentic to gain and lose the weight. What did you think of the book and/or movie? What do you think about the way Rosamund gained and lost weight? Let us know in the comments section.