For years, Brad Huffaker obsessively exercised, up to five hours a day. Then he stopped eating for up to 12 hours a day. Eventually, he began gorging each evening on any food he could find in the house and making himself vomit it all back up -- a cycle he repeated up to eight times throughout the night.

Finally, last summer, Mr. Huffaker realized he had an eating disorder and needed help. But after scouring the Internet and researching 20 in-patient facilities, he found only one that specialized in treating men. Mr. Huffaker, a 24-year-old in Knoxville, Tenn., says finding a male-focused center was important because he felt ashamed dealing openly with his problem in front of women. "It's much easier for me to eat in front of guys," he says.

Even amid a growing understanding of the incidence of eating disorders in men and boys, experts say there is a dearth of treatment options for male patients. Only a handful of residential treatment centers have programs that focus on men and boys. Many centers are reluctant to treat men at all. And there has been virtually no research done on males with anorexia or bulimia.

Because these conditions are still considered female problems, even the criteria for identifying eating disorders are female-oriented. The diagnostic guidelines many professionals use include questions about menstruation and female body image. There are efforts to change these guidelines to be more inclusive of men's issues. But eating-disorder experts and male patients say the current lack of treatment programs has a profound impact on the chances of recovery.

For many years, conventional wisdom held that one-tenth of patients with eating disorders were male. But in February -- in the first national survey of eating disorders -- Harvard researchers reported that males represent as many as one-quarter of anorexia and bulimia patients and close to 40% of binge eaters. That would mean 300,000 men in the U.S. over 18 get anorexia at some point in their lives, and two million become binge eaters, the researchers say. No one knows if the numbers of male eating-disorder patients are actually growing, or if more men and boys are simply coming forward to seek treatment. But the few programs that specialize in men say they are seeing increased enrollment.

Both males and females with eating disorders experience similar biological and psychological problems, say experts. But men and boys often manifest their symptoms differently. While females obsess over calories and weight, males typically focus on muscle and body fat. Mr. Huffaker, who is 6 feet 7 inches tall and got down to 180 pounds, liked that he had defined muscles, taut skin and just 5% body fat.

Unlike females, males have a variety of body images they may be trying to obtain. "Some want to be wiry like Mick Jagger; some want to be lean like David Beckham, and some want to be really buff and bulked, like Arnold Schwarzenegger," says psychiatrist Arnold Andersen, director of the eating-disorders program at the University of Iowa in Iowa City.

The stigma of having an eating disorder can be even greater for males than for females, which typically makes them even more reluctant to seek treatment. "Society sees this as a girl's disease," says Lynn Grefe, chief executive of the National Eating Disorders Association, a Seattle-based nonprofit. "If a guy suffers, he's embarrassed."

Researchers at the University of North Carolina at Chapel Hill reviewed clinical trials for eating disorders conducted between 1980 and 2005, and the findings -- recently published by the International Journal of Eating Disorders -- are striking: The 32 clinical trials for anorexia included 816 females and 23 males; 47 studies of bulimia looked at 2,985 females and 69 males; 26 studies of binge eating disorder included 1,008 females and 87 males. The eight medication studies on anorexia included 293 females and only one male.

"We have abandoned men," says Cynthia Bulik, one of the authors of the review and director of the eating-disorder program at the University of North Carolina at Chapel Hill.

In the primary handbook for diagnosing mental disorders -- the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, known as the DSM-IV -- the criteria to assess for anorexia involve female-specific traits, such as amenorrhea, or menstrual irregularity.

Experts say that the screening tests developed by researchers for the disorders are gender-biased, too. "Most questions are designed with female concerns in mind," says Dr. Andersen. " 'Do you worry about hips?' 'Do your thighs jiggle?' Instead of, 'Do you worry about muscle?' "

In response, several experts, including Dr. Andersen, are developing gender-neutral screening tests. And there is a committee being formed by the American Psychiatric Association to examine the eating-disorder criteria in the DSM-IV and determine what should be revised in the next edition -- DSM-V, to be published in 2012. That committee is likely to look at gender differences, says William E. Narrow, DSM-V task force research director.

Because of the lack of gender-specific research, eating-disorder experts say they have no proof that the treatment for males should differ from that for females. A successful regimen of care is often individualized and involves psychotherapy, family therapy and antidepressants.

"The bigger problem arises if the male patient needs to be treated in a group setting," says B. Timothy Walsh, a psychiatrist and director of the eating-disorders research unit at the New York State Psychiatric Institute at Columbia University Medical Center in New York City. "It can be difficult for a young man if he is the only one going through the process with a group of young women."

Mark Grennell experienced this first hand. As a teenager, he began restricting his food, in an effort to look lean and "cut" (with well-defined muscles). This behavior led to fasts that lasted days at a time and, ultimately, an inability to keep food down. Three years ago, when the 5-foot-10 young man weighed 93 pounds, he decided to seek treatment. He chose an eating-disorder center in Southern California that accepts males but treats mostly females.

At times, he was the only male in a therapy group. Often, he says, he had trouble relating to how the women felt fat. He wasn't focused on his weight as much as on controlling his body. And he was troubled by what he calls the "feminist slant" of the therapists, blaming men and media images for pressuring women. "They said that society teaches women to be thin, to be ashamed of their bodies," says Mr. Grennell, 24 years old. "That really made me uncomfortable because that's not my experience."

Such issues are often cited by experts who say single-sex group therapy is preferable. At Remuda Ranch in Wickenburg, Ariz., which treats only women, David Wall, director of psychological services, says that women, for instance, often find it difficult to talk about issues such as sexual abuse and body image in front of male patients.

Indeed, some experts say that single-sex groups can be powerful tools to healing for men. "They provide a safe place, a way for men to come in and talk about issues relevant to men," says Brad Kennington, a therapist in Austin, Texas, who formed a therapy group for men with eating disorders last year that met for several months.

"Women will talk about how they are no longer ovulating, which is not a symptom in men," says Mr. Kennington. "Men will talk about the role of men in a relationship and how that role gets questioned when they have an eating disorder."

Although men are often reluctant to seek treatment, some eating-disorder centers are seeing an increase in male patients. At Rogers Memorial Hospital, in Oconomowoc, Wis. -- which has one of the best-known all-male eating-disorder programs -- the number of male eating-disorder patients has grown 50% in the past three years; males now represent 25% of the 200 or so eating-disorder patients a year in the residential program.

Rogers, which is where Mr. Huffaker sought help, treats about seven males at a time. They live separately from the female patients. Ted Weltzin, a psychiatrist and director of the eating-disorder programs, says males have different body-image issues than females, need more help overcoming their compulsive exercise habits and often have a harder time understanding the emotions behind the disorder.

Male-only therapy lets them "see other males cry in group therapy and then go to dinner and talk about sports," he says.

Only a handful of other clinics around the country have specific programs for males. At River Oaks Hospital, in New Orleans, males have their own group and body-image sessions. But they share other group activities with females, including anger-management sessions and post-meal therapy. "I believe the mix of males and females is helpful," says Susan Willard, clinical director of the hospital's eating-disorders treatment center. "It broadens the perspective for both populations."

The University of Iowa's eating-disorders program, where 14% of the patients are male, has a separate psychotherapy group and strength-training for males, and men can have testosterone replaced if they need it. Men who are malnourished may have low testosterone, says Dr. Andersen, which makes it difficult to build and maintain muscle.

At the Center for Eating Disorders at Sheppard Pratt, in Baltimore, which has four to six male patients in residence at a time, double the number from five years ago, doctors hold male-only group sessions when they have enough patients. "We focus on what it's like for males to live in a society that focuses on these disorders as women's issues," says Harry Brandt, director of the center.