The former Downton Abbey actor also donned a heavy muscle vest for the part.
Beauty And The Beast star Dan Stevens ate four roast dinners a day for his big screen Disney role.
The former Downton Abbey actor, 34, plays the Beast in the movie, also starring Emma Watson, 26, as Belle.
He told Radio Times magazine that he wore steel-capped stilts to give him height and a hot, heavy muscle vest for the part.
“It was a pretty athletic job for me,” Dan said.
“I was physically conditioning my legs to be on stilts for 12 hours a day and also conditioning the rest of me so that I didn’t waste away – I was losing so much fluid from sweating.
“Underneath the muscle vest, I wore a special cooling vest, similar to what Formula One drivers wear, with refrigerator-style tubing.
“I would overheat, especially when we were dancing, so between takes there was a little tube that could be plugged in to ice-cold water to cool me down.”
And he added: “I was honestly eating four roast dinners every day, just to keep any form of physicality.”
The actor also told how he drew inspiration from dealing with one of his three children for the role.
“I was going home in the evening after filming and dealing with my son Aubrey being in the terrible twos and there is a lot of that that feeds into the performance,” he said.
“There’s a stroppy, spoilt quality to the Beast – not that my son is spoilt. I don’t think he is.
“Everyone goes through the terrible twos … But I wondered, what if someone was indulged and pandered to at that age and it carried on their whole life?”
Dan said of moving to the US since leaving Downton Abbey: “I feel that I’ve learnt an awful lot in the last five years – things that I could never have learnt by exclusively working in England.”