Bulik said men with eating disorders face extra hurdles because doctors don't think to diagnose them properly to begin with. They're also ashamed because there's a misconception that eating disorders are woman's diseases, and that they are more prevalent among gay men.
"Eating disorders really don't care what your sexual orientation is," Bulik said.
She said she sees male patients with eating disorders every day.
"This is not something that is rare," she said. "I think we need to get past the misperception that this is something that's rare, because it does a huge disservice to boys and men."
She said she once had a male patient whose mother brought him to a pediatrician because she thought he had an eating disorder, but the pediatrician told her that was impossible because "boys don't get eating disorders." So the doctor gave the boy a battery of tests to find a rare disease he didn't have.
Texas therapist Jacquelyn Ekern said many of her male patients fell into anorexia or bulimia after sports -- such as wrestling -- pushed them to be a certain weight in a hurry. The men who develop eating disorders after crash dieting also have underlying psychological factors that predispose them toward eating disorders, such as depression, anxiety or having a parent with an eating disorder.
"Genetics load the gun and environment pulls the trigger," said Ekern.
Even worse, men are less likely to seek help once they realize they have a problem, said Dr. Vicki Berkus, who directs Eating Disorder Programs for CRC Health Group, which has facilities in Arizona, California, Nevada and North Carolina.
"I think for males it's that males don't talk about feeling dizzy," she said. "That old 'pull yourself up by the bootstraps, real men don't have issues,' which is totally false."
Ekern agreed. "They're less likely to come forward with it because some of them feel emasculated by it," she said. She who founded Eating Disorder Hope, an awareness organization, in 2005. "However, they shouldn't. It is an equal opportunity disease, and there are so many factors that can contribute."
Berkus said men can hide their eating disorders more easily because they didn't grow up helping their mothers in the kitchen the way girls often do, so it's a room they can avoid without anyone noticing. Men and boys also don't talk about their bodies or show them off in clothes the way girls do, so they can hide behind jeans and baggy T-shirts.
However, when men participate in mixed gender therapy groups in her treatment center, they find that they're still battling the same diseases even though they show it differently, Berkus said.
Bulik said the latest Diagnostic and Statistical Manual published by the American Psychiatric Association this spring is expected to exclude the missing menstrual cycle from its anorexia description. That's a step toward destroying the misconception that only women can get it.
Today, Avon considers himself recovered from anorexia, and has written two books about it. He regularly does speaking engagements to talk about how men can get eating disorders, too, and he has become a spokesman for the National Eating Disorders Association.
"The guys are out there," he said. "I always find people saying that they didn't think anybody else felt the way they felt. They felt so alone. It's opened their eyes that this is an illness that is not just something to keep in the closet."
ABC Tweet Chat on Eating Disorders
At 1 p.m. ET today, Dr. Richard Besser, ABC News' chief health and medical correspondent, will host a one-hour tweet chat to discuss eating disorders. Experts from the National Eating Disorder Association, National Association of Anorexia Nervosa and Associated Disorders, Mayo clinic will be tweeting their advice and support, along with representatives from eating disorder clinics, programs and support groups. If you are suffering from an eating disorder or have recovered from one, come share your story. Get advice and help others. You don't need to be a Twitter expert to follow the conversation or jump in with questions and comments of your own. To learn how you can participate, click here.