updated 04/18/2011 AT 2:00 PM ET
•originally published 04/18/2011 AT 2:50 PM ET
It wasn’t weightlifting that wore out Chris Hemsworth as he bulked up – big time – to star in Thor.
The actor, 27, says non-stop food consumption was the key to his 20 lbs. weight gain.
“I feel as if I’ve been busy, but all I’ve been doing is eating all day,” Hemsworth tells Men’s Health in its May issue. “Eating when you’re not hungry and taking in that amount of food is exhausting.”