Looks like Mike Tyson's ear-chomping days are officially behind him. The former professional boxer and world heavy weight champ has become a vegan.

Tyson, who actually committed to the strict vegetarian diet last year and has lost 100 pounds, offered this perfectly logical and cogent explanation for giving up his animal-based diet in a clip from Tuesday's "Oprah: Where Are They Now?

"Becoming a vegan gave me another opportunity to live a healthy life. I was so congested from all the drugs and bad cocaine, I could hardly breathe, [I had] high blood pressure, [was] almost dying [and had] arthritis. And once I became a vegan all that stuff diminished," Tyson, 46, said.

But he has not always waxed so poetically on the topic of veganism.

"I just threw up the white flag," he told Ann Curry on "The Today Show" last year in an attempt to explain why he took up the diet. "Too many prison cells, too many jails, too many lawsuits, too many bankruptcies, too many women, too many venereal diseases, too many everything. I got tired … of every time my prostitute girl got back from a trip, I had to sleep with her. I'm going to live a different life."

(Image Credit: Image credit: Gabriel Olsen/Getty Images)

Registered dietitian Cynthia Sass gives Tyson's dietary switch a thumbs up but said he'd have to eat carefully to get adequate amounts of protein, zinc and calcium. And in order to avoid becoming "Low Iron Mike," she recommended eating plenty of beans, legumes and nuts.

"It's a good idea to pair iron-rich, plant-based sources such as spinach and broccoli with citrus and other good sources of vitamin C in order to enhance iron absorption," she pointed out.

Sass said she has seen plenty of people declare they are vegan only to subsist on frozen vegan pizza, vegan ice cream and other vegan junk foods.

"You get rid of cholesterol and saturated fat but you don't increase fiber, antioxidants and vitamins," she said. "That's not really healthier."

This doesn't appear to be the case with Tyson, who, in the Oprah Winfrey clip, is shown with his third wife, Lakiha Spicer, whipping up a vegetable smoothie and snacking on fruit. Not a slice of beef or Evander Holyfield in sight.

The Tyson interview aired Tuesday night on the OWN channel. You can also catch Tyson in his one man show, "Mike Tyson: Undisputed Truth," now touring nationally with director Spike Lee.