Work-life balance has become a major priority for Gen Z, with younger workers increasingly placing a premium on time away from their jobs, in some surveys ranking it above pay. But Panda Express cofounder Andrew Cherng has never placed much value on work-life balance.

Even at 78, the self-made billionaire restaurateur has long embraced the demanding schedules and relentless work ethic that helped him build the largest Asian-American restaurant chain in the U.S.

“It was hard when I had no business, there was no income,” he said after recently being asked by NBC News how to avoid burnout. “But even then, I wasn’t burned out because, you just work, go to work, and [if] you have a like a 12-hour day, you go home, you sleep well—I mean that’s life.”

His experience sits at odds with public-health research on extended hours: a 2021 joint study by the World Health Organization and the International Labour Organization linked working 55 or more hours per week to higher risks of stroke and heart disease, attributing an estimated 745,000 deaths to long working hours in a single year.

That mindset helped him and his wife, Peggy, turn a single family-run restaurant into a nearly $7 billion-a-year global chain over five decades. It has also helped lift their combined net worth to an estimated $6.6 billion.

How two immigrants turned $60,000 into an empire serving 148 million pounds of orange chicken a year

Andrew Cherng was born in Yangzhou, China, in 1948. When he was 5, his family fled to Taiwan, and eight years later they moved again, this time to Japan.

He eventually made his way to the U.S. and enrolled at Baker University in Kansas to study mathematics. There, he met his future wife, Peggy, who was born in Burma and later became his business partner. She now serves as Panda Express’ co-CEO. The couple later earned master’s degrees from the University of Missouri.

“Every holiday I had, I worked in New York, waiting tables in a restaurant,” Andrew recalled to Fortune in 2013. “My father was a chef but hadn’t owned his own business. I didn’t like that. In my heart of hearts, I knew I wanted to be in business.”

Peggy later pursued her PhD and worked briefly as an engineer for McDonnell Douglas and Comtal, which was acquired by 3M, while Andrew began building his career in the restaurant industry. He moved to California to work for his cousin, putting in seven days a week at the restaurant for $800 a month.

After a year, Andrew decided to strike out on his own with his parents. Together, the family scraped together $60,000 from savings and a Small Business Administration loan and opened Panda Inn in Pasadena, California, in 1973.

“The whole family—my parents, a brother and sister—all worked at the restaurant for free,” he recalled. “We lived in a two-bedroom apartment in San Gabriel and didn’t have any money. Peggy would come to visit, and we got married in 1975.”

The restaurant’s expansion was slow at first, but by 1983, the first Panda Express opened in a shopping mall in Glendale, California, and the concept gradually took off. In 1985, Panda grew from five locations to nine in a single year.

Peggy’s engineering training proved central to that growth. As the chain expanded, she computerized store operations and helped standardize recipes and processes across locations—an early, data-driven approach widely credited with supporting the chain’s consistent scaling.

Today, Panda has more than 2,600 locations around the world and employs over 55,000 people. In 2025 alone, the chain served 148 million pounds of its signature orange chicken. The Cherngs built the business without taking money from outside investors.

Work-life balance rejected by many top founders

The Cherngs are not the only business leaders who have embraced an all-consuming approach to work and credited that commitment with helping fuel their success.

Nvidia co-founder and CEO Jensen Huang has also said that work-life balance is essentially nonexistent for him and that he is constantly thinking about his chip-making business.

“I work from the moment I wake up to the moment I go to sleep. I work seven days a week,” Huang said in a 2024 interview with Stripe CEO Patrick Collison.

That relentless focus has helped transform Nvidia from a computer graphics company first conceived at a Denny’s into one of the world’s most valuable companies, with a market capitalization of more than $5.5 trillion. Huang’s personal net worth is estimated at nearly $190 billion.

Elon Musk has made a similar case, arguing in a 2018 tweet that “nobody ever changed the world on 40 hours a week” and describing stretches of up to 120-hour weeks during Tesla’s Model 3 production ramp. In China, Alibaba founder Jack Ma in 2019 defended the tech industry’s grueling “996” schedule—9 a.m. to 9 p.m., six days a week—drawing pushback that included Chinese state media noting that forcing employees onto such schedules violates the country’s labor law.

Huffington Post founder Arianna Huffington recently echoed that sentiment to Fortune, saying she does not believe people with truly engaging jobs can simply shut their laptops at 5 p.m.

“I don’t think there is anybody with an interesting job who can do that,” Huffington said. “For you, or me, or most people with interesting jobs, there is never a time when you have a natural ending to the day.”

The same idea extends beyond business. Will.i.am, the Grammy Award-winning music artist, previously told Fortune that Gen Z should forget about work-life balance if they want to build something new.

“If you’re trying to build something that doesn’t exist, it’s about dream-reality balance,” he said. “Work-life balance means that you’re working for somebody else’s dream. You just have a job supporting somebody else’s dream, and you want to balance your work and your life.

“But if it’s dream-reality balance, then it’s not work,” Will.i.am added. “It’s a dream that you’re trying to put into reality, and you’re ignoring your current reality.”

The tension has persisted as major U.S. employers roll out return-to-office mandates and Gen Z becomes a steadily larger share of the workforce.

This story was originally featured on Fortune.com