Christian Bale lost 28kg in four months, dropping to 54kg by eating a can of tuna or an apple per day. Daniel Day Lewis studied Czech, broke two ribs by hunching over for weeks, learned to live off the land, and took lessons as an apprentice butcher. And Robert DeNiro worked as a New York taxi driver for three months, boxed competitively, and gained a third of his body weight.
Amateurs.
Nils van der Linden 