John Goodman’s trainer talks weight loss, intervention at cemetery: ‘Dig your grave’

People are amazed by John Goodman’s remarkable transformation after he showed off his dramatic weight loss on the black carpet of the 62nd Monte-Carlo TV festival on Sunday.

But the 70-year-old actor didn’t make this change at the snap of a finger — it took hard work, dedication and a very dramatic intervention.

“People think this is overnight, but most people make a contribution to weight management, but they don’t make a commitment to it,” Goodman’s trainer Mackie Shilstone told The Post.

Goodman and Shilstone live just two blocks away from each other in the Garden District in New Orleans, and the 72-year-old fitness expert first helped Goodman lose 85 pounds prior to Hurricane Katrina hitting in 2005.

After Katrina hit, Goodman “really fell off” and regained the weight he had shed.

“John decided that he was going to make a commitment,” Shilstone, America’s Premier Sports Performance Manager and Career Extension Specialist, said. “I’ve known John for a long time, and 85 pounds coming off and then regained, it didn’t work. So I said, ‘What am I gonna do?’”

Shilstone is an influential fitness, wellness and sports performance expert — not an actor — “but John was my friend and my neighbor, so I said to myself, let me become an actor for a moment.”

Most people would expect to go with their trainers to a gym or recreational center, but Shilstone took his client somewhere slightly more unconventional for an intervention: a cemetery.

The trainer took Goodman for a walk, shovel in hand, and went to an area of the cemetery where there was, of course, no graves — but plenty of dirt.

“I said, ‘John, here’s a shovel. You told me you’re going to recommit yourself and follow this plan,’” Shilstone shared with The Post. “I said, ‘I want you to dig your grave. Until you dig your grave, you won’t understand what it means to live.’”

He continued to tell Goodman, committing to being an actor: “John, do you really know who I am? Do you have any idea who you’re next to? You notice there’s no wind? And there are no birds, nothing, no sounds, you don’t even hear cars.”

Goodman allegedly seemed confused, and Shilstone laughed recalling the memory: “I guess the good Lord was playing the game with me.”

“I’m death, and I’ve come to give you a second chance,” Shilstone told Goodman. “You can dig your grave now and I’ll cover you over and we’ll be done with this, or you can use this shovel and cover it over and move on with your life and take it back.”

“John, you have a lovely daughter, you have a lovely wife, and you’ve been successful, but you’re not gonna make it,” he continued to tell the actor under the guise of death. “I want you to close your eyes and think you can never say another word to your daughter and wife. It’s all over. I’ve taken that from billions of people over time. I will give you one more chance.”

Shilstone shared that he had to be Goodman’s friend first and foremost, because “friends can tell each other tough things.”

The health and fitness guru set the “Righteous Gemstones” actor up with equipment in his home in California so he can continue his lifestyle adjustments while there.

“I said, ‘John, just remember this. I’m always around. I always know where you are. I can find you anytime, your day will come. But it’s not now,’” he told Goodman, committing to the bit of his “death” character.

“I haunt him,” Shilstone laughed. “And that’s the true story.”

Shilstone, who wrote the 2012 book “Stop Renting Your Health—Own It: A Three Step Approach,” emphasized that it’s important to take ownership of your health before it owns you so you can “move on and be done” — which he said worked for Goodman, who previously weighed 392 pounds.

He said he had to find a regimen that Goodman could live with and be committed to, and after they figured that out, the “Roseanne” star found that he could be comfortable with himself.

“Commitment over contribution,” Shilstone said. “Anyone can lose weight. It has to be a smart, committed person to keep it off, especially as you age.”

Shilstone noted that success doesn’t mean you keep the weight off, which was evident the first time Goodman lost weight prior to Hurricane Katrina, saying “he failed” initially.

But once Shilstone “became death” and made Goodman take ownership of his own health and fitness — including lab studies, preventative medication, doctor appointments and workout routines — the actor is now transformed.

“[John’s] made a commitment to live his life,” Shilstone shared. “To me, he is a model.”