Aretha Franklin has denied reports that her drastic weight loss is due to gastric bypass surgery.

The legendary soul singer, who was recently honored at the Grammy Awards, underwent surgery for a mystery illness back in December, amidst rumors that she was battling pancreatic cancer, and returned to the spotlight a reported 80 lbs. lighter.

In a two-part interview with 'Access Hollywood,' which airs tonight and tomorrow, though some of the quotes have already hit the 'Net, the 68-year old singer addressed the "crazy" rumors. "Definitely not -- and would not," Aretha exclaimed. "I heard that [rumor]. I said, 'That is crazy."

Aretha has yet to reveal the nature of the surgical procedure, and while she admits that it is likely her weight loss was a result of "the surgery that I had," she continues to scoff at the notion that she has received the controversial weight-loss surgery.

"It definitely was not the bariatric or, what is it, gastric by -- Yeah, I can't even tell you the correct name of it," she blustered. "It's really not necessary to talk about one's personal medical [health]."

In an interview with Wendy Williams last week, Aretha claimed that her weight loss was the result of an extreme change in diet, attitude, and mystery surgery. "The doctor did say to me, he said, 'Mrs. Franklin, you are going to feel better than you have felt maybe in 10 or 15 years,'" she told Williams. "'The surgery that you had is going to add 15 years to your life.'"

Aretha has scheduled her first post-op concert for May 28 in Buffalo, N.Y. Her highly anticipated new album, 'Aretha: A Woman Falling Out of Love,' is slated for release earlier that month.

Watch Aretha Franklin's 'I Say a Little Prayer'