Yo! Guys, listen up. You may not need bulging biceps, awesome abs, or colossal quads to be attractive to the ladies.

Researchers from Harvard Medical School in Boston, the University of Innsbruck in Austria, and the Salpetriere Hospital in Paris, France, suggest that the pursuit of rippling muscles by men in Western countries is due, in part, to media portrayals of lean and muscular male physiques. Perhaps weight loss is in order... it's pure health.

In addition, the researchers say that Hollywood's most "masculine" stars in past decades, such as James Dean and John Wayne, were not as muscular as today's male action stars. And, boys' action figure toys, such as GI Joe, have grown progressively leaner and more muscular over the past 40 years.

College-age men in the United States, Austria and France indicated they want and believe that women prefer a body with at least 27 more pounds of muscle than they possess, according to the researchers.

But a related pilot study suggests that women in Austria prefer a less muscular male physique, and anecdotal evidence suggests that their American and French sisters agree. Both studies appear in the August issue of the American Journal of Psychiatry.

Harrison G. Pope, Jr., M.D., the principal author of the research, says that men likely will continue their trips to the gym because of competition among men and the images portrayed in the media and by the film industry.

"If, during your entire life, you're fed a diet of media images that big, muscular bodies are what an ideal man should have, you believe that is what you're supposed to look like," Dr. Pope says.

The consequences of this cultural shift could be more than sore muscles or torn tendons, the researchers warn. Vulnerable men could develop psychiatric disorders such as muscle dysmorphia, which is a distorted body image, or steroid abuse.

Keith G. Kramlinger, M.D., a psychiatrist at Mayo Clinic, Rochester, Minn., likens the pressure on men to become muscular to the pressure that many women feel to be thin, which can lead to eating disorders such as anorexia or bulimia.

"Beyond these issues," Dr Kramlinger adds, "the preoccupation to beef up may lead to the exclusion of other activities and relationships that are so important to a healthy, balanced life.

"It's also important to remember that healthy physical conditioning is a balance of strength, stamina and flexibility."