Michael Fassbender (lost 42 pounds)

Credit: Everett

In 2008, hunger, Fassbender plays Bobby Sands, a young prisoner, the second hunger strike Provisional Irish Republican Army made in 1981 and died after 66 days without food. Off-screen, Fassbender went on a hunger strike in front of his own: the combination with 900 calories per day, plus exercise (jumping, yoga, walking) led to a weight loss of 42 pounds. "It's not a psychological prison," he said of the process, the final weight. A reported 127 pounds.

The Bottom Line:
Theoretically Fassbender lose weight in a recommended way - by reducing the calorie intake and exercise. But he took the extreme. "You should not take the weight in starvation mode," says Kushner.