Anna Ryan eats a low-fat diet and exercises regularly, but she recently started piling on the pounds — as much as 14 pounds in one month, the Daily Mail reported.

So Ryan, 42, started limiting herself to just 1,200 calories a day, but it didn't help and her weight ballooned to 266 pounds.

Then, two years ago, she was diagnosed with a rare condition called Sleep-Related Eating Disorder (SRED). Doctors believe that for the past 20 years she has been getting up in her sleep, walking to the fridge and eating as many as 2,000 calories in a single night.

Psychological disorders and some medications used to treat other disorders (such as insomnia or depression) can lead to SRED, according to the Mayo Clinic. Click here to learn more.

Eating cheese, chocolate, butter and meat, Ryan has no control over what she eats.

She now suffers from high blood pressure and diabetes as a result of the overeating.

"My sleep-eating is putting my life at risk," she said. "I've tried so many things to stop it, but nothing works."

Dr. Scott Eveloff, a sleep specialist, diagnosed her with the rare sleep disorder which is believed to affect up to 3 percent of the population. Eveloff suggested Ryan reduce the amount of food she keeps in the house and put locks on her refrigerator and cupboards. She also trying medication.

Click here to read more from the Daily Mail.