Rebel Wilsonâs doctor revealed how the Hollywood star lost five stones and steered her life into a healthier direction. The âPitch Perfectâ star, who came to fame with her role as Fat Amy in the 2012 rom-com, shared her weight loss results on her Instagram this week. The selfie portrays the Australian star on the set of her upcoming movie âSenior Yearâ wearing a pink satin gown that shows off her incredibly slimmer frame. - Advertisement - The star previously weighed in at around 16 and a half stone, while being 5ft 2in tall. However, by the end of last year, she had lost more than four and a half stone and reached her target weight of 11 and a half stone.