To some, Salomon's 5-foot-2-inch, 170-pound body would be a professional deal-breaker. After all, are chubby dietitians or portly physicians in any position to advise others how to get healthy?
Her supporters say she is being treated unfairly; after all, many previous surgeon generals - most of them men - weren't so skinny themselves.
But with the nation's obesity crisis worsening, some advocates say it's increasingly critical for health care workers and those with visible, influential roles to "walk the walk" and serve as role models.
"A doctor doesn't need to be perfect, but it'd be hard for me to take financial advice from a CPA who had just filed for bankruptcy," said Dr. Timothy Harlan, medical director of the Tulane University School of Medicine, who says he believes physicians should make a genuine effort to be healthy.
On the other hand, Harlan said, he once had an obese partner who was well loved by his overweight patients. Many doctors and psychiatrists listed on a "fat friendly health professionals" Web site are overweight themselves, which some argue makes it easier for them to understand what their patients are going through.
"The weight of a health professional is irrelevant," said Roki Abakoui, assistant director for clinical services at Northwestern University's Counseling and Psychological Services and an activist for size acceptance. "People come in all shapes and sizes," and everyone should be represented in health professions, she said.
Moreover, some research widely circulated in the online "fatosphere," an arm of the fat acceptance movement, suggests that carrying around a little extra flesh doesn't necessarily mean you're unhealthy. Weight, the activists say, is just one measure of health and is affected by genetics in addition to lifestyle choices.
"Weight and health are not the same thing," Abakoui said. "There are thin people who are unhealthy and there are fat people who are healthy."
Yet substantial research has shown that weight is inextricably linked with both personal and economic health. Obesity, which disproportionately affects African-Americans and other minority groups, is a risk factor for a number of chronic diseases, including diabetes, cardiovascular disease and some cancers.
The costs to the U.S. health system caused by obesity could be as high as $147 billion each year, according to a study released Monday at the U.S. Centers for Disease Control and Prevention's Weight of the Nation conference.
Patients, meanwhile, have more confidence in their doctors if they aren't obese, according to a 2003 study in the journal Preventive Medicine.
"If (health officials) don't hold themselves accountable to healthy standards, what are they going to be able to do for me?" asked Leesa Drake, 42, of Chicago. "These are presumably people to whom I would pay money for their services and expert opinions. I want to know that they know what they're talking about by walking the talk themselves."
Drake, an endurance athlete, might naturally be drawn to a fit-looking physician or personal trainer because "patients initially judge doctors on the basis of superficial demographics such as age, sex and similarity to oneself," said Dr. Ronald Epstein, a professor of family medicine at the University of Rochester Medical Center who studies how to improve patient-physician communication and relationships. Others struggling with weight issues might be intimidated by a doctor who runs marathons.
Ultimately more important, said Epstein, is the ability to communicate. "Later we tend to connect on the basis of personality, a deeper level," he said. "The better the communication, the less those superficial differences seem to matter."
Those bonds influence how willing patients are to work closely with physicians, said Dr. Michael Dansinger, a nutrition and obesity researcher at Tufts Medical Center.
"What makes a physician credible is whether they practice what they preach and heed the lifestyle recommendations they propose, said Dansinger. "Whoever the surgeon general is can set the best example by actually practicing the lifestyle recommendations that are necessary in order to turn around an obesity epidemic. That's slightly different than judging someone on weight."
The U.S. Department of Health and Human Services has declined comment on flap over Benjamin's weight - which has not been disclosed - but it provided a statement calling her "a highly qualified physician who has dedicated her life to providing care to her patients. She is a role model for all of us, and will be an outstanding surgeon general."
Salomon, 65, who calls herself "Fatty Matty" on her blog "Diary of a Dieting Dietitian," says she wouldn't want to be lectured by a naturally lean person who had never known any moments of despair over being too fat. "I was never destined to be a twig. I'm muscular and short. I don't have long limbs," she wrote in an e-mail. Salomon is working out six days a week for two hours a day in preparation for the power lifting event in the Arizona Senior Olympics, but she remains candid about her size in hopes of using her personal struggles to help others.
"I am fat because I eat too much," she admitted. "I exercise plenty but I just eat too much. In fact, burp, I just did."