Al Sharpton's 167-pound weight-loss inspiration? Matt Lauer

Al Sharpton says he went from 305 pounds to 138 pounds.

While the Rev. Al Sharpton’s influence in the social justice movement is still large, his body is not.

At his peak, Sharpton, 59, was 305 pounds, but he told Matt Lauer on TODAY Wednesday that he is all the way down to 138 pounds. He also cited a specific inspiration for his weight loss.

“I gave up meat, I started watching my diet, I work out,’’ Sharpton said. “I get up every morning and watch you Matt, and I say, ‘I want to look like that.’’’

“I bet there’s other motivation,’’ Lauer joked.

Sharpton began his weight loss in 2009, exercising regularly and cutting out meat from his diet. In 2001, he had shed 30 pounds during a hunger strike when he was imprisoned for protesting the U.S. government’s use of Vieques Island in Puerto Rico for bombing exercises. However, he wasn’t able to keep that weight off and realized he needed more exercise and a better diet to slim down. He became a vegan, which he said has contributed to him trimming down to less than half the size he once was.

In his new book, “The Rejected Stone,’’ Sharpton writes about his physical transformation and also the lessons he has learned during his time as an activist and civil rights leader involved in some of America’s most high-profile cases.

'I was there for the rejects': Rev. Al Sharpton looks back on the learnings of his legacy

One of those cases was Tawana Brawley, an African-American teenager who falsely accused six white men of having raped her in 1987. Sharpton supported Brawley and had harsh words in public for the prosecutor in the case. In 1988, a grand jury found that Brawley was not the victim of rape or any sexual assault and may have fabricated her claims.

“This book is not about cases, this book is about lessons, and I did talk about the lessons of Brawley,’’ Sharpton said. “What I dealt with is that even though I believed her and represented what I believed, you still don’t make it personal. I may believe you’re wrong, but to get into name-calling and to get into denigrating you I think is something that you’ve got to say, ‘Wait a minute, that is not going to help the cause.’’’

Sharpton, host of MSNBC's "PoliticsNation," said he knows he is a polarizing figure and his involvement in any case can bring strong reactions from both sides, but sometimes that is necessary.

“I think some double-edged swords are needed because you’re going to be able to draw the kind of attention you need because you need someone that can go in that will make people say, ‘We need to pay attention to that,’’’ Sharpton said. “If someone doesn’t go in, the victim will not be heard at all.”

Sharpton also discusses his childhood in his new book, describing how he was a bit of an outcast because of his precociousness as a Pentecostal preacher.

“I started preaching when I was 4 (years old),’’ he told Lauer. “It was odd for my friends to have their parents come hear me preach on Sunday, and it was a little rough getting girlfriends, too.”