The split is difficult but amicable, they say. The couple have a son, Noah, who is 13.

Mr. Zimmern is bracingly frank about where his marriage went wrong. They met 18 years ago at a cookware store in Minneapolis and married two years later. He was leaving the restaurant business and starting a career in food media, a shift he thought the would allow him more time to be a family man. It had the opposite effect, especially as his career took off.

“I wasn’t there for my wife, and I wasn’t there for my son,” he wrote in an email. “My wife gave me a thousand chances to make it right.” He underestimated his own ambition, he wrote, and “the strange dependence I would come to have surrounding all the attention and the merry-go-round of being a public person.”

It’s something he used to talk about with Anthony Bourdain, who killed himself in June. Mr. Bourdain’s Travel Channel show “No Reservations” started two years before his, and over the years they became friends. They would huddle up when their paths crossed, exploring the dark places inside both of them, and the perils of using the road and fame to fill them.

“We shared a very, very deep feeling of wanting to get off this crazy roller coaster, but at the same time knowing that this was our work,” Mr. Zimmern said in an interview on the day Mr. Bourdain died.

The death has intensified Mr. Zimmern’s quest to learn balance, something he says is elusive for chefs, athletes, actors and other celebrities. “In all honesty, it’s at the core of what the impostor syndrome is all about,” he said. “People telling you all the time how great you are, how much you’ve accomplished, screaming, ‘We love you! You’re the best!’ from the car speeding by. But at the end of the day, on the inside, you don’t always feel good about yourself.”

His solution is to double down on health and sobriety. “I want to be the best dad and the best ex I can be.”

Still, his ambition runs deep. So does his taste for business, which he started honing as a young drug dealer at the Dalton School, an exclusive prep school on the Upper East Side he graduated from in 1979 .