Aretha Franklin covers the March 7, 2011 issue of Jet Magazine

*Fox411 has sought a health expert to weigh in on Aretha Franklin’s 85 pound weight loss, and he says that given her age and the amount of weight she’s lost — simple diet and exercise alone are not enough to have brought on such drastic results.

Beverly Hills-based surgeon, Dr. Lawrence Koplin (who does not treat Franklin) noted that losing such a vast amount of weight in a short period of time is incredibly challenging with diet and exercise alone.

“Losing this amount of weight with exercise and diet would require a strict, strict team, and is said to be impossible especially those above 40 with a slowed metabolism,” Koplin told the column. “Surgical correction is the fastest way to see an 85 pound weight decrease in just a few months.”

Franklin’s weight loss followed a major health scare late last year, after the 68-year-old underwent surgery for an undisclosed ailment in December after complaining of debilitating side pains. Fans and the media speculated that she was suffering with pancreatic cancer, a claim she consistently denied.

But Internet rumors are now swirling that indeed Franklin was not diagnosed with cancer, but became seriously ill – canceling a slew of concerts and appearances including the recent Grammys – due to complications surrounding a gastric bypass surgery procedure.

A rep for Franklin did not respond to request for comment, and she has so far declined to elaborate on what caused her recent emergency surgery. An insider told the column that her mystery illness is even being kept from those who work closely with Franklin.