Ben Stiller is a private guy so when he talked about his diet (back in 2012) and his prostate cancer (in 2014) fans were concerned, then relieved to learn that he was cancer-free, and in the years since, it appears the Severance director has made it his business to live a healthy, fit, active life.

Back in 2012, Ben Stiller revealed to Conan O'Brien that he follows a mostly vegan diet. He also wrote two years later on his blog that thanks to an early screening test for prostate cancer, he had been diagnosed with early-stage prostate cancer. and treated successfully.

“I got diagnosed with prostate cancer Friday, June 13th, 2014. On September 17th of that year, I got a test back telling me I was cancer free. The three months in between were a crazy roller coaster ride with which about 180,000 men a year in America can identify.”

The reason he went public about treatment was to encourage men to get screened earlier than the now-recommended age of 50, and to not be shy about talking to their doctors about prostate cancer, which is often free of symptoms until it progresses.

Prostate cancer is the second most common cancer in men in the United States after skin cancer, and one of the deadliest if it goes undetected. In their lifetime, 1 in 7 men in the US will be diagnosed with prostate cancer and since most men don't like to talk about this personal topic, the medical community is urging men to talk to their doctors about whether and when they should be tested for the disease. Stiller believes early screening saved his life.

“This is a complicated issue, and an evolving one,” Stiller writes. “But in this imperfect world, I believe the best way to determine a course of action for the most treatable, yet deadly cancer, is to detect it early.”

Stiller believes that if he had waited until he was 50 to get a prostate-specific antigen (PSA) test, as the American Cancer Society recommends, "I would not have known I had a growing tumor until two years after I got treated,” Stiller wrote. “If he had followed the U.S. Preventive Services Task Force guideline, I would have never gotten tested at all, and not have known I had cancer until it was way too late to treat successfully.”

Stiller is "Mostly Vegan" and Appears at Plant-Based Hot Spots

Stiller also doesn't love to talk about his diet, but by all indications, being "mostly vegan" with a little fish is another way the actor/director stays healthy, combined with a fitness regimen that keeps him trim, fit, and able to run like a track star in his movies.

Of course, the characterization of eating “mostly vegan” leaves room for fish and occasionally dairy or other animal products, but Stiller appears to have doubled down on eating healthy in the years since his cancer diagnosis. Now, he incorporates as many plant-based meals into his diet as possible, but still enjoys the occasional serving of fish. Over the years, the Zoolander star has hinted that he enjoys vegan food as much – if not more – as he did a decade ago.

Admiring Stiller's fitness in his running sequence in The Watch, Conan asked if he had any secrets for staying fit. Stiller noted that he started eating vegan, along with his wife and sometime co-star Christine Taylor. She has also talked about their plant-based journey.

“It really has changed our energy level,” she revealed to People Magazine in 2012. “Sometimes you don’t realize it until someone says it to you, like, ‘your skin looks amazing.'”

Stiller and his daughter were recently spotted eating at the new, popular plant-based restaurant, PlantPub – a partnership between vegan chefs Mary Dumont and Matthew Kenney, and plant-based entrepreneur Pat McCauley and Sebastiano Cossia Castiglioni.

Stiller and John Travolta brought their daughters to Plant Pub, to celebrate an early birthday. PlantPub markets itself with the slogan: Eat Plants, Drink Beer. The restaurant has two locations, the first in Cambridge, Massachusetts, and the other opening at Fenway Park this week.

Stillers Celebrate a Birthday With Vegan Food

The vegan restaurant serves plant-based variations of classic pub food including bungalow chicken caesar wraps, Impossible burgers, and more. Ella Stiller called the restaurant a “vegan heaven.”

"It was really exciting having him here and so cool that he was just as approachable and nice as he could have been," PlantPub co-owner Pat McAuley tells People Magazine.

Before the Stillers’ birthday celebration, McAuley and co-owner Mary Dumont teamed up with chef Kenney to open their second location across from Fenway Park – the home of the Boston Red Sox. Now, PlantPub is a hotspot for both vegans and celebrities. Joining the Stillers’ appreciation for vegan eats, other celebrities including Zendaya have been spotted patronizing the plant-based eatery.

Plant-Based Benefits for Prostate Cancer

Research shows that eating plant-based significantly lowers the risk of ever developing prostate cancer.

One study found that men who were vegetarians showed a 31 percent lower risk of ever developing prostate cancer, whereas pescatarians had a 20 percent lower risk. Other studies show that avoiding dairy – commonly associated with unhealthy hormone contents – can lower the risk of prostate cancer by up to 60 percent. Experts show that replacing meat and dairy products with pinto beans, avocados, and other plant-based foods can significantly improve health and lower cancer risks.

Stiller spends more time these days working for the plight of refugees around the world so fans who follow him will hear more about the needs of others than his own personal life.

For more stories on cultural icons who have gone plant-based check out The Beet's Lifestyle and Culture section.

Wondering if your favorite celebrity follows a vegan diet? Check out The Beet's list of plant-based celebrities including Paul McCartney, Sandra Oh, and more. 

Sandra Oh and 20 Others It Might Surprise You to Learn Are Plant-Based

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