Last October, John Goodman stepped out looking slimmer than ever at the "Trumbo" London premiere, and the 63-year-old actor has been doing a fantastic job keeping the weight off.

At the time, Goodman, who once weighed 400 pounds, revealed that he had lost more than 100 pounds through diet and exercise. As someone who had always struggled with his weight, he finally found the inspiration he needed to make some real changes. While promoting his new film "10 Cloverfield Lane," which was filmed more than a year and a half ago, he described what he's been doing over the past several months to drop the weight.

"I just stopped eating all the time," he said. "I'd have a handful of food and it'd go in my mouth. I was just eating all the time. I was just eating alcoholically. In the old days, I would take three months out, lose 60 or 70 pounds, and then reward myself with a six-pack of Bud or whatever and just go back to my old habits. Then, this time, I wanted to do it slowly, move, exercise. I'm getting to the age where I can't afford to sit still anymore. And it gives me the energy to work, 'cause work is very draining."

As for his motivation to change, Goodman said, "I just got tired, sick and tired of looking at myself. You're shaving in the mirror and you don't want to look at yourself. It gets dangerous."

Goodman also spoke to Howard Stern about his lifestyle and what made him decide to be healthier. "I decided to stop stuffing food into my mouth every five minutes," he said. "Turns out, I was just eating all the time. Anytime I had my hands open or free, I shoved something in my mouth. It's all crap."

He then explained how he now eats smaller meal portions and uses his at home elliptical often. "It's been a year and a half, I did it slowly," he continued. "I took it slow. I just wanted to change my lifestyle. You look in the mirror everyday and go, 'I gotta deal with this the rest of the day, I gotta deal with this schmuck?"

Even though he revealed last year that he had lost more than 100 pounds, he won't say how much he's lost in total. The motivation seems to be working so far, but he's still skeptical on whether he can stay this way.

"Just wait another six months and I'll be back to normal," he said. "That's the way it usually goes. I have no idea how much I lost. I didn't weigh myself. Clothes fit nice and I can go to nice clothing stores and buy too much stuff."