Have you ever wondered what its like to be an actor? How demanding a role can be, which often requires specific skills. Expectations can often mean having to make huge physical transformations to get in to character for a particular part.
This often requires an actor to go through extreme circumstances to either lose or gain weight, build muscle or study a person.
We have complied 30 of the most dramatic transformations these actors have endured for a specific role, many who have won prestigious awards for their efforts.
#1 Chris Hemsworth:

Thor
#2 Christian Bale:

The Machinist
#3 Chris Pratt:

Guardians Of The Galaxy
#4 Jake Gyllenhaal:

Southpaw
#5 Jonah Hill:

Maniac
#6 Matthew McConaughey:

Dallas Buyers Club
#7 Natalie Portman:

Black Swan
#8 Jared Leto:

Dallas Buyers Club
#9 Tom Hardy:

Bronson
#10 Jared Leto:

Chapter 27
#11 Charlize Theron:

Monster
#12 Demi Moore:

G.I. Jane
#13 J.K. Simmons:

Justice League
#14 Chris Hemsworth:

In The Heart Of The Sea
#15 Tom Hanks:

Castaway
#16 Edward Norton:

American History X
#17 50 Cent:

All Things Fall Apart
#18 Matthew McConaughey:

Gold
#19 Zac Efron:

Baywatch
#20 Robert De Niro:

Raging Bull
#21 Vincent D’Onofrio:

Full Metal Jacket
#22 Michael Fassbender:

Hunger
#23 Ryan Reynolds:

Blade: Trinity
#24 Christian Bale:

American Hustle
#25 Anne Hathaway:

Les Miserables
#26 Daniel Radcliffe:

Jungle
#27 Ben Kingsley:

Gandhi
#28 Emile Hirsch:

Into The Wild
#29 Jake Gyllenhaal:

Nightcrawler
#30 Renee Zellweger:

Bridget Jones: Edge Of Reason