To play hunger-striking political prisoner Bobby Sands in his first Steve McQueen collaboration Hunger, Fassbender consumed 900 calories a day in sardines, berries and nuts… until his weight plateaued and he had to live on even less.
Playing a cancer patient for Things Fall Apart, the normally-jacked rapper dropped from 214 pounds to 160 in just nine weeks thanks to a diet of liquids and three hours spent on the treadmill every day.
For 2009′s Triage, Farrell played a combat photographer who returns home from Kurdistan, haunted and emaciated. Farrell lived off two tins of tuna a day, which he supplemented with black coffee and diet Coke for “energy” on set.
Although we prefer to remember Welles as the tanked sparkling wine enthusiast from those perfect commercial outtakes, he also directed some movies. In one of them, a little seen gem called Citizen Kane, he had to lose about 50 lbs to play a younger version of the eponymous Charles Kane. Welles subsisted on orange juice, boiled eggs and salads for a month to do so. Hopefully he celebrated his return to eating with some French champagne (or an exquisite California facsimile).
(Photos via Getty, Wenn, Pacific Coast News)