The Scottish star famously bulked up to play a Spartan warrior in 300 and he stunned film fans recently by sporting a slender new look to portray surfing icon Rick 'Frosty' Hesson in new film Mavericks.
But he wishes everyone was more focused on his performances than his physique.
Butler tells HollyScoop.com, "They (critics and gossips) love to get involved in things like that. It would be nice if they appreciated it.
"I go through all that work and do it for different roles, and get big for 300 or get heavier for a role, or slim down for a role... It'd be nice if they went, 'Well look, he's committed'."
And he insists that it isn't easy to get in shape for a movie role: "I ate my last meal in October and I run about 40 miles a day. I'm joking. It's just doing a lot of cardio and... watching what I eat. I stopped lifting big weights and I'm doing yoga. It's not hard to be in shape... (but) it's hard to be in really good shape."