Former 'Roseanne' actor, John Goodman has lost 100 pounds by opting a no alcohol lifestyle, sugar free diet and rigorous workouts, according to Celebrity Health & Fitness.

Goodman, who previously weighed 400 pounds looked extremely svelte when he appeared at the red carpet for the premiere of his new movie 'Trumbo' on Thursday. Rumors then emerged that he slimmed down after he underwent a weight loss surgery.

However, the 63 year old actor who once said that he is trying to lose weight through a healthy means, credits exercise, sugar free diet and alcohol free lifestyle for his weight loss success.

John, who grew tired of being obese, said he wanted to improve his well- being. "I know it sounds sappy, but it was a waste," Goodman told People. "It takes a lot of creative energy to sit on your *ss and figure out what you're going to eat next. I wanted to live life better."

Goodman practiced sugar free diet after he quit drinking and smoking in 2007. He then asked for help from a fitness expert and author of 'The Fat-Burning Bible,' Mackie Shilstone, who trains celebrities, including Serena Williams, Celebrity Health & Fitness reported.

Shilstone was impressed with Goodman and praised him for hitting the gym six days a week and for religiously following the no sugar diet.

"John is very agile," the couch said. "He remembers what it feels like to be extremely heavy and it's something he doesn't want again."

Speaking at the David Letterman Show, Goodman said he feels much healthier because he exercises regularly and he noticed that his weight dramatically dropped time after time.

He also said that he is very happy with his weight loss, "I just ordered some nice slacks," John said. "I finally got them and they're too big now."

Goodman plays Hollywood producer Frank King in his new film, other stars, include Helen Mirren, Elle Fanning and Louis C.K.