Venus Williams switched to a raw vegan diet last year

An expanding list of celebrity vegans is transforming the popular image of the "no meat, no dairy" lifestyle that has often been seen as the choice of holier-than-thou tree-huggers in plastic shoes.

Bill Clinton and his daughter Chelsea, Michelle Pfeiffer, Alec Baldwin, Demi Moore, Ben Stiller, Ellen DeGeneres, Portia De Rossi, Tobey Maguire, Betty White, Joaquin Phoenix, Pamela Anderson, Mike Tyson, Ted Danson, Venus Williams, Woody Harrelson, Rosie O'Donnell, Robin Williams, KD Lang, Russell Brand, Alicia Silverstone, Carl Lewis, Casey Affleck, Erykah Badu, James Cromwell, Alanis Morissette, Russell Simmons, Fiona Apple, Sandra Oh, Bryan Adams, Jessica Chastain, Moby, Carrie Underwood, Ed Begley Jr, Daryl Hannah, Thom Yorke (Radiohead), Abbie Cornish, Erik Roberts, Andre 3000 (Outkast), Chrissie Hynde, Grace Slick, Daniel Johns (Silverchair) ... the list of TV and movie stars, musicians, politicians and athletes who have stopped eating meat and dairy products continues to grow.

The latest celebrity to make the switch to a vegan diet is US talk-show host Rosie O'Donnell, who suffered a potentially fatal heart attack on August 14.

O'Donnell also spoke to Dr Caldwell Esselstyn, author of Prevent and Reverse Heart Disease, in which the former surgeon and Olympic rowing champion argues that a vegan diet can reverse cardiovascular disease.

Former US president Bill Clinton read Esselstyn's book before switching to a plant-based diet following his quadruple bypass surgery.

"I had been playing Russian roulette," says Clinton, who now consumes no meat, no dairy and no eggs.

"I like the vegetables, the fruits, the beans, the stuff I eat now," Clinton told CNN. "All my blood tests are good, my vital signs are good and I also have, believe it or not, more energy."

Actress Michelle Pfeiffer (Scarface, Dangerous Liaisons) recently stopped eating meat and dairy products after reading the same book.

Seven-time Grand Slam tennis champion Venus Williams switched to a raw vegan diet last year after being diagnosed with Sjogren's syndrome – an autoimmune disease which left her with fatigue so overwhelming that "sitting in a chair was a huge effort." Williams told CBS, " I've made huge improvements since I was first diagnosed ... changing my diet has made a big difference."

Comedian Russell Brand, a longtime vegetarian, became a vegan last year after watching Forks over Knives - a documentary about the health effects of eating animal-based and processed foods.

One of the more unlikely converts to veganism is former world heavyweight boxing champion, "Iron" Mike Tyson - notorious for biting off part of the ear of rival Evander Holyfield during a 1997 title fight. Tyson turned vegan in 2009 and last year told Fox News that he feels "awesome, incredible."

"When you find out about all the garbage you've been eating ... no wonder I was crazy all those years," he says. "The drugs didn't help either," Tyson jokes.

Others including actor Robin Williams and musician Ozzy Osbourne also switched to a vegan diet because of health concerns, but many celebrities cite moral and ethical grounds for their veganism.

"Around 450 billion animals are factory farmed on our planet every year," says talk show host Ellen DeGeneres. "Dairy cows are kept constantly pregnant to produce milk, while their calves, considered by-products, are put to death almost instantly.

"Animal farming is the number one cause of climate change in the world and has a 40 per cent larger carbon footprint than all global transportation – every car, truck, bus, train and plane combined," says DeGeneres.