Richard Simmons' Mysterious Disappearance Due To Birth Defect He's Hidden From Public, Documentary Claims

The mysterious disappearance of Richard Simmons is due to a painful disease he has been battling since birth, according to a new documentary.

In the documentary, titled "TMZ Investigates: What Really Happened to Richard Simmons," TMZ managing editor Fabian Garcia claimed that the fitness guru has been a recluse in his Hollywood Hills home since he first went missing, dealing with a birth defect he has kept secret from the public all his life, the New York Post reported.

"Something that happened to him at birth is directly connected to his disappearance — a birth defect that significantly affected one of his legs," Garcia said, according to the outlet. "He was born without a full set of bones in his foot and it causes physical and emotional problems."

Meanwhile, documentary producer Charles Latibeaudiere claimed Simmons has gained so much weight since holing up in his home, and it's left him too unfit and insecure to show up and make a comeback. "Richard found comfort in food and he gained a lot of weight. And that put a lot of stress on his knees," he explained, according to the outlet.

In his 1999 memoir "Still Hungry After All These Years: My Story," the pop culture legend opened up about how his love for food had led to his obesity at an early age and impacted his overall sense of self-worth. "I went through a lot of hurt as a child. I was the largest child in school. At the age of 15, I was 200 pounds. I went to my first Halloween party dressed as a couch. I was the one made fun of. I felt very bad about myself," the New York Post quoted him as saying.

The TMZ documentary, which is available on Fox and Hulu, reportedly reveals that after his painful childhood, Simmons decided to use the birth defect in his foot as motivation to adopt a healthier lifestyle, which includes moderate eating and exercise. As he moved to Los Angeles in his early 20s, he opened his own gym and paved the way for a new era of "hookup" gym culture, in which he held classes for people of all shapes and sizes.

Simmons has stayed out of the limelight for eight years. He disappeared in February 2014 and has never been seen in public again. Since he vanished, there have been conspiracy theories as to where he might be and why he had left the spotlight. One of the wildest rumors surrounding his disappearance is that he's being held hostage by his housekeeper.