Oprah Winfrey is the focus of her new TV special on weight loss, and tells how she has been the victim of public shaming and humiliation for decades.

An Oprah Special: Shame, Guilt, and the Weight Loss Revolution aired Monday night and began with a stark and powerful reflection on Winfrey's own weight loss journey, including the highs and lows that have been fodder for tabloids and comedians for years.

“I have to say that I have taken on the shame that the world has given me,” Winfrey said, speaking to a live studio audience. “For 25 years, making fun of my weight was a national sport.”

Winfrey recalled a particularly painful day in 1990 when she saw herself on the cover TV Guide for the magazine's “Best and Worst Dressed” list.

“I remember at first thinking, 'Oh, look! There's me on the cover.' And then I read the headline that Mr. Blackwell – the tastemaker of the time – called me 'lumpy, lumpy and downright stupid,'” Winfrey said. “I was ridiculed on every late-night talk show for 25 years and for 25 years on tabloid covers.”

Winfrey then read just a handful of the mean, hurtful and downright cruel headlines published over the past two decades, mocking her weight and speculating about her health.

The hurtful spotlight led her to become obsessed with her appearance and go to extremes to lose weight.

“In an effort to fight all the shame, I starved myself for almost five months, then wheeled out that wagon of grease that the internet will never let me forget,” Winfrey said, recalling a particularly infamous episode of her talk show remembered. “And after you lost 67 pounds on a liquid diet, the next day, y'all very the next dayI started to win it back.”

The special itself featured interviews with several medical experts, as well as people who have struggled with their weight for years, in an effort to combat the stigma surrounding the increasing use of weight-loss medications.

In the run-up to Monday's special, the 70-year-old Winfrey spoke with ET at the 55th NAACP Image Awards about the TV special.

“I'm so excited about this show that I'm doing… about shame and guilt and the weight loss revolution,” Winfrey said. “I'm so excited about it because, as you know, I've been in this business for years and been disgraced myself. And I just want people to be liberated, and know that, for so many people in this country who are suffering from weight and obesity, it's really not your fault; it's your brain.”

“So once you figure that out, you can get help to help you deal with it, however you want to do it,” Winfrey added. “So I want people to stop being blamed for the choices they make about their health.”

“We had to shut it down,” Winfrey told ET about medical experts weighing in on the drug conversation. “They've been using these drugs for 20 years. I didn't know that. They've been using these drugs for 20 years and we're just now hearing about them.”

The special comes shortly after Winfrey stepped back from Weight Watchers board of directors for a decade after she made her recent announcement use of weight loss medications – which has had a remarkable impact on her own health and figure.

“I'm very excited about it,” Winfrey said of the availability of drugs designed to treat obesity and promote greater weight loss. “Because I have suffered so long, struggled so much and done everything.”

An Oprah Special: Shame, Guilt, and the Weight Loss Revolution aired on ABC on March 18 and will be available on Hulu the following day.