Renée Zellweger – 40 Pounds

For her role in the film Bridget Jones’s Diary, actress Renee Zellweger needed to gain over 30 pounds to fit the part better. The professional she is, Zellweger did so, and the film went on to become an absolute smash. However, after shooting, Zellweger knew that she had to get back in shape as quickly as possible, in order to gain new parts.

After Bridget Jones, Zellweger hired a personal nutritionist who also worked as her fitness trainer. Before long, the actress lost all the extra fat, a total of 40 pounds! Thankfully, Zellweger did not have to gain the same amount of weight for the film’s later sequels.