The mogul opened up on ‘The Jamie Kern Lima Show’ about why she chose to “accept” being told to lose weight on national television

Oprah Winfrey is reflecting on her first appearance on The Tonight Show — and how host Joan Rivers’ comments about her weight made her think, “I should be shamed.”

Winfrey — who believed she had just lost a role in The Color Purple due to her weight — shared on the podcast The Jamie Kern Lima Show that she’d appeared on The Tonight Show in 1985 to discuss the success of her TV hit A.M. Chicago.

Instead, the conversation turned to Winfrey’s size.

“Joan Rivers turns to me and she says ‘Tell me why are you so fat?’ ” Winfrey, 70, told Lima, the author of the bestselling book Worthy and the founder of IT Cosmetics.

“On national television,” Winfrey emphasized, adding, “and I don’t know what do with that.”

“I just did, like, ’Oh, I just love potato chips, Joan.’ ”

Winfrey continued, saying that Rivers, who died in 2014, told her “shame on you.”

Winfrey then says she “agreed with Joan Rivers,” who recalls that the host said, ‘“I’ll let you come back if you lose 15 lbs. You need to lose 15 lbs.’ “

“She says to me on national television,” Winfrey continued. “And I accept it. I accept that I should be shamed, because how dare me, be sitting up here on The Tonight Show.”

Winfrey said she and Rivers “agreed that I was gonna go away and lose 15 pounds. And of course, I didn’t lose the 15 pounds. I went and ate my way to another 10 pounds.”

Winfrey shared that she had gone away to “this health retreat” — which she explained “at the time, they called them ‘fat farms’” to lose weight.

While there, Winfrey says she tried to accept that her weight had cost her a role in The Color Purple. When she’d finally let go of the possibility of appearing in the film, she received a phone call that changed everything.

It was The Color Purple’s producer, Steven Spielberg, who told Winfrey, “‘I hear you’re at a fat farm.’ “

“ ‘You lose a pound,’ ” he told her, ” ‘You could lose this part.’ ”

Winfrey says the phone call was a full-circle moment for her — because she’d finally “let go” of the part when she got the call.

“The instant I let it go was the greatest life lesson I have ever received, because I physically felt the release,” said Winfrey.

“The second I did that it changed,” she said — and Winfrey did, of course, land the role of Sofia, which earned her an Academy Award nomination.

“That became my grounding teaching for the rest of my life and career,” she shared. “Do everything you can, work as hard as you can, and then let it go.”