"PRIMETIME: MEDICAL MYSTERIES" EXAMINES MORBID OBESITY AND HOARDING, WEDNESDAY, JANUARY 17 ON ABC

Imagine the inability to stop eating or gaining weight - reaching over 1,000 pounds - or a compulsion to collect junk non-stop. This week "Primetime: Medical Mysteries" looks at medical conditions where people are virtually powerless before some of the most basic human urges. John Quinones and Jay Schadler report on morbid obesity and hoarding, respectively, on "Primetime: Medical Mysteries," WEDNESDAY, JANUARY 17 (10:00-11:00 p.m., ET) on the ABC Television Network. The series continues through January 31.

How could a human being weigh over 1,000 pounds and still be relatively healthy? "Primetime" reports on how morbid obesity occurs - how people can grow without stopping, and whether they can ever recover from it. To understand this condition, Quiqones sits down three morbidly obese people. He travels to Mexico to meet Manuel, the heaviest man in the world, who weighed 1,200 pounds at his top weight. He also checks in with Michael Hebrenko, who lost 800 pounds and then gained it all back; seven years after Hebrenko went from 1,000 to 198 pounds in 19 months, he found himself so heavy again that rescue workers needed to tear down part of his house to remove him -- today he is in an obesity rehabilitation center in New York fighting the battle daily. And in the third case, the program looks at what happens when those who lose the weight find themselves with 45 pounds of extra skin. Is a total body lift the solution to lead a normal life?

And: What if a person's brain wouldn't let them throw away even a scrap of paper, a candy wrapper, an old, expired coupon? Jay Schadler reports on people with hoarding syndrome. Hoarders are unable to throw anything away -- their brains go into panic at the thought. He interviews a woman who uses her own house just for storage. "Primetime" takes viewers inside a hoarder's brain -- what happens when their possessions get shredded?

The hour will also feature a real medical mystery designed for viewer participation. This segment, entitled "You Be the Doctor," allows viewers to assess medical clues and vote online or by text message on a diagnosis. This week a young woman who seems to have something like the flu ends up in intensive care, and no matter what antibiotic they give her, it doesn't work.

Terence Wrong and Ann Reynolds are the senior producers of "Medical Mysteries." Rudy Bednar is the executive producer.