The 28-year-old Australian comedian, who is best known for her role as Brynn in Bridesmaids, lost 10kg last year as the face of weight loss company Jenny Craig, but has since had to stop her diet and exercise due to a movie contract.
Wilson told The Sunday Telegraph: " I have been filming a musical called Pitch Perfect in Louisiana for the past few months... and for my contract in that movie I had to stay the same size.
"I'd lost 10kg and then had to maintain that for the whole movie, which is quite difficult. I was lucky in that I didn't really have any health issues in that I had to lose weight or my heart would explode, but it was more just feeling more comfortable in myself."
Wilson said that Australian casting agents used to be "prejudiced" about her look, but has found it to be an asset in Hollywood.
"When I walked into the US agency I am with, they saw me and thought, 'We don't have anyone who looks like you, so we are going to accept you'," she explained. "Then once you are talented and people find out about it, hopefully people will start writing roles for me."
Wilson said that she will be back on her diet as soon as filming on Pitch Perfect finishes and aims to reach 80kg by the end of this year.
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