Feb. 2 (HealthDay News) -- Binge eating tops the list of eating disorders affecting Americans, with the first-ever national survey on eating disorders finding it much more prevalent than either anorexia or bulimia.

Binge eating -- a condition where people undergo frequent, uncontrolled eating binges without purging -- affects 3.5 percent of women and 2 percent of men during their lifetime. The condition is strongly linked to obesity.

There have been previous studies that looked at the prevalence of anorexia nervosa or bulimia nervosa in the population, "but for binge eating, there had been no previous studies," said lead researcher Dr. James I. Hudson, director of the Biological Psychiatry Laboratory at McLean Hospital and a professor of psychiatry at Harvard Medical School.

"These are really the first hard numbers for the prevalence of this disorder," he said during a teleconference to announce the findings on Wednesday.

According to the new survey, binge eating is more common than either anorexia nervosa, which strikes 0.9 percent of women and 0.3 percent of men, or bulimia nervosa, which affects 1.5 percent of women and 0.5 percent of men.

Binge eating "is associated with severe obesity and all the complications of obesity," Hudson said. "And, it's often chronic."

That said, the rates of all eating disorders have been increasing, according to Hudson. "In addition, eating disorders are related to mood disorders, anxiety disorders, impulse control disorders and substance use disorders," he noted.

More troubling is the fact that less than half of those with a history of an eating disorder said they had ever received treatment, Hudson said.

In the survey, Hudson's team collected data on almost 9,300 people from across the United States who participated in the National Comorbidity Survey Replication. Among those interviewed, 3,000 answered questions about eating disorders. The report is published in the February issue of Biological Psychiatry.

The researchers found that the average duration of anorexia was 1.7 years, compared with 8.3 years for bulimia and 8.1 years for binge eating disorder.

"Binge eating is a true eating disorder. It is a major public health problem," Hudson said. "There is a strong genetic component to binge eating disorder and, because of this, we might be able to treat or prevent binge eating and thereby prevent many cases of obesity."

One expert believes the survey will bring more attention to eating disorders, prompting the U.S. government to spend more dollars in research on the causes and treatment of these conditions.

"These results back up things that groups like ours have been saying for the past several years," said Marc Lerro, executive director of the Eating Disorders Coalition. "There has been relatively little definitive research done on eating disorders."

Lerro is happy to see that these conditions are getting more recognition. "People with eating disorders are compromised in how they interact in school, in the workplace," Lerro said. "For some, it's really a disabling condition that sometimes leads to death."

That binge eating is the major problem did not surprise Lerro. "The stereotype that [people with] eating disorders are just pencil-thin girls is really not comprehensive," he said.

Lerro believes the federal government should be keeping track of the number of people in the United States who suffer from eating disorders. This year, the U.S. government is spending only $21 million on research into treatments for eating disorders, he said.

"This survey is really a wakeup call for the federal government to do more, like counting the number of people who die each year due to an eating disorder, counting the number of people who are struggling with eating disorders, and funding research to determine what is effective in treating eating disorders," Lerro said.

Another expert believes that eating disorders are even more common than the survey suggests.

"Eating disorders are more common than many people realize, and the prevalence is increasing," said Dr. Ellen Rome, head of the section on adolescent medicine at the Cleveland Clinic. "If you look at all of mental health, the spectrum of eating disorders is among the most commonly found health challenges that individuals face."

Moreover, people with eating disorders also have many social problems related their condition, "from shame, guilt, denial, the egocentricity of the illness that doesn't let them see how it's affecting their lives," Rome said.

Binge eating is closely tied in with the U.S. obesity epidemic, Rome added. "We see any form of disorder eating as a maladaptive coping strategy," she said. "Eighty percent of obesity is genetic. So, genetics loads the gun. And the prevalence of binge eating goes hand-in-hand with obesity as one contributing factor. Many people use binge eating to fill up an empty space."

Rome also believes that more funding is needed to study the causes and treatments of eating disorders, including the genetic and social components of the problem and what treatments work best.

"We are just scratching the surface," she said. "We need better treatments across the whole spectrum from under-eating to obesity. There is just so much more we need to know."

SOURCES: James I. Hudson, M.D., Sc.D., director, Biological Psychiatry Laboratory, McLean Hospital, professor of psychiatry, Harvard Medical School, Boston; Marc Lerro, executive director, Eating Disorders Coalition, Washington, D.C.; Ellen Rome, M.D., M.P.H., head of section, adolescent medicine, Cleveland Clinic, Ohio; February 2007, Biological Psychiatry