Sleeping-pill users face kitchen chaos as they binge eat in sleep

The problems of overweight Americans are usually ascribed to poor diet and a lack of exercise. But new research suggests another possible culprit: the country's addiction to sleeping pills, the most popular of which may cause some people to binge eat in their sleep.

The drug in question is Ambien, manufactured by the French company Sanofi-Aventis, for which 26 million prescriptions were written by American doctors last year. Alas, according to two separate medical studies in Minnesota, it may have an unfortunate side-effect for a few users - causing them to indulge in bouts of nocturnal feasting without knowing a thing about it the next morning.

In one instance, a woman put on 100lb. She thought her family was responsible for the morning-after mess in the kitchen. Only when her sons and husband caught her in the act was she convinced otherwise.

Another so-called "Ambien zombie" - a Minneapolis woman called Judie Evans - took the drug while she was recovering from back surgery. Despite being in a cast, and needing assistance to get out of bed in her waking hours, she would get up during the night and raid the refrigerator. At first she accused nurses of stealing the food. Only when her son came to stay did she understand what was happening. "During the day, I couldn't even make it to the bathroom myself," she told The New York Times.

Sanofi-Aventis sells $2.2bn (£1.2bn) worth of Ambien a year in the US, and insists the drug is safe. It vows to fight a class action lawsuit brought by some users, saying it issues a warning of possible sleep-related eating disorders with the pack.

Some doctors urge patients to install a chime on their bedroom door, to alert them when they are on an unconscious food foray.

But even that may not be enough. A third sufferer explained to ABC News last week how she would find food scattered over her kitchen when she got up. "I would eat things like raw eggs, uncooked rice, bags of [potato] chips, loaves of bread, candy. When my husband took the food and hid it, I would open cans of vegetables and eat them. Anything I could get my hands on, it didn't matter." Like other victims she had no memory of what happened - only the evidence of torn wrappers, crumbs and smears of chocolate cookies on the sheets.