Ashton Kutcher lost 12 lbs. training for marathon: Mila Kunis 'has been super supportive'

Ashton Kutcher has lost over 10 pounds since he started training for the 2022 TCS New York City Marathon — and wife Mile Kunis approves. Kutcher opened up about his body transformation weeks after revealing he previously battled a rare autoimmune disorder.

"The biggest change physically has been the transfer of muscle mass from upper body to lower body. I've lost about 12 pounds," he tells Entertainment Tonight, adding "my wife has been super supportive."

Kutcher, who shares daughter Wyatt, 7, and son Dimitri, 5, with Kunis, is running in the November marathon to raise money and awareness for Thorn, an organization that aims to end child sexual exploitation.

"My baseline 'why' comes down to leaving life better than what it was given to me. My daily motivator is my kids and family," Kutcher shared.

"Surrounding myself with a support system makes hard things much easier," he added. "Setting a pace that you can sustain is not the same thing as working as hard as you can."

Earlier this month, Kutcher opened up for the first time that he was diagnosed with a "super rare form of vasculitis."

"Like two years ago, I had this weird, super rare form of vasculitis, that like knocked out my vision, it knocked out my hearing, it knocked out like all my equilibrium," Kutcher revealed on Running Wild With Bear Grylls: The Challenge, later adding: "[I'm] lucky to be alive."

According to Mayo Clinic, vasculitis involves inflammation of the blood vessels affecting one or several organs. After news of his health ordeal made headlines, Kutcher clarified he's "all good."

"You don't really appreciate it, until it's gone," Kutcher told Grylls. "Until you go, 'I don't know if I’m ever going to be able to see again, I don't know if I'm ever going to be able to hear again, I don't know if I'm ever going to be able to walk again.'"

MORE: Ashton Kutcher speaks out after health battle makes headlines