Shortly after Amy Koechler learned how to walk, she started doing something very unusual.
After falling asleep, Koechler would get up and toddle to the kitchen almost every night, find a snack, and eat it -- without ever waking up. While everyone has heard of sleep walking, Amy suffered from a related condition that's almost a secret. It's called SRED, Sleep Related Eating Disorder, also known as sleep-eating.
More than a million Americans suffer from this strange affliction, and most of them are women. Why they do it remains a medical mystery. However, doctors are pretty certain that genetics, rather than hunger, play a role. In Koechler's case, she inherited sleep-eating from her mother Shirley.
Koechler, now 24, recounted what it was like to grow up sleep-eating almost every night.
While fast asleep, "I would get up in the middle of the night and I would grab Girl Scout cookies," she said. "I would get my mom and I would pretend to have a tea party. And she became really frustrated with me because I would constantly wake her up."
Mom Shirley Koechler remembers how "Amy would come upstairs and she would flop her feet like a duck. We knew she would be sleep-walking. And then she'd have these eyes -- and you knew she wasn't awake . And sometimes she would look at you and scream: 'I'm hungry!'"
Koechler sleep-ate her way into adulthood. Her nightly trips to the kitchen became more frequent.
"It was not once a night, it was seven, eight, nine times a night," she recalled. There were times where I would get up and it would be probably a half hour after I'd fallen asleep."
But somehow, even though Koechler ate in her sleep for two decades, she didn't gain extra weight. For Anna Ryan, the consequences of her sleep-eating have been much more devastating. Ryan said that she gained 60 pounds in the year and a half that she has been eating in her sleep.
At first, she didn't even know that she was doing it.
Every morning, "I would wake up and it felt like I hadn't gone to bed," she said.
She had no idea why she was waking up exhausted or why she was unable to keep her eyes open during the day. When her doctor recommended that Ryan participate in a sleep study, she thought it was unnecessary. But the results of the study surprised her. It turns out Ryan was up most nights and she was eating in her sleep.
Like most sleep-eaters, Ryan had no recollection of her nightly trips to the kitchen. But she wanted to see it for herself. She invited "Primetime" to set up night-vision cameras in her home to record her nocturnal journeys.
To her amazement, the cameras captured five different trips to the kitchen in a two-night period. The footage revealed Ryan, with a vacant stare, wandering into the kitchen and ransacking the cabinets. Ryan was eating, then filling her arms with snacks and taking them back to her bed.
Ryan's doctor, Scott Eveloff, said her nighttime gorging demonstrated an almost textbook case of sleep-eating.
"If you'll notice on the video, Anna does pass by the fruit, passes by several other more nutritious foods and then not only takes the non-nutritious food but, unfortunately, takes a lot of it and eats an almost a slovenly manner," Eveloff said. "That is classic sleep eating behavior."
Watching the video of herself sleep-eating for the first time, she was shocked by the images.