Women -- especially poor women -- may be more likely to develop a binge eating disorder when they are pregnant, according to a new study.

A long-term study of 100,000 pregnant women in Norway found an increase in new incidences of binge eating disorder that began during pregnancy.

Previously, small clinical studies had suggested that eating disorders go into remission during pregnancy, just as some pregnant women spontaneously quit smoking cigarettes.

Binge eating differs from cravings that pregnant women often report, said Dr. Cynthia M. Bulik, who led the study from the University of North Carolina. It involves consuming large amounts of food and feeling out of control.

Binge eating disorder is also associated with health problems such as anxiety and depression, insomnia, and chronic pain.

Unlike bulimia, sufferers of the disorder don't purge what they eat.

The findings were published in the August 2007 issue of Psychological Medicine. The research was supported by grants from the National Institutes of Health.