Recently, my colleague Benoît Monin and I studied doctors who advertise their fitness online. Past research has shown that people worry that those who claim the moral high ground will look down on others whose behavior seems unfavorable by comparison. For example, meat-eaters worry that vegetarians will judge them because of their diet. We wondered: Could emphasizing fitness make doctors seem “healthier than thou” and turn off patients?

We thought that people who are overweight and obese might be particularly sensitive to judgment from doctors. Unlike unhealthy habits such as smoking, weight can’t be hidden. Research shows that negative attitudes toward people who are overweight are surprisingly prevalent among health professionals. So potential patients who are overweight might be especially turned off by doctors who show off healthy habits.

To test this idea, in research recently published in the Journal of Personality and Social Psychology, we turned to the real-world examples of physicians practicing what they preach on the website for Kaiser Permanente, the largest managed care organization in the United States. Here, patients choose among dozens of doctors from self-descriptions only a few sentences long, making any information provided consequential. We asked adults who were overweight or obese to rate a sample of these profiles. Some physicians emphasized their fitness in these profiles, while others did not.

We found that participants who were overweight believed that the fit doctors would disapprove of patients with unhealthy habits, and as a result overweight participants preferred physicians who did not advertise their fitness. Interestingly, in our studies, doctors who emphasized their healthy habits were no more appealing to patients who were not overweight. So health care practitioners showing off a healthy lifestyle didn’t seem to draw in patients as might have been expected, and even drove away some.

This research documents that promoting that you practice what you preach can backfire. Doctors who advertise their commitment to fitness in their own lives can seem critical of patients with less-than-perfect health, and inadvertently threaten patients who are struggling. Well-meaning doctors who are proud to be leading by example could be repelling exactly the people they may hope to inspire. As a result, many individuals may be avoiding doctor visits and not getting the care they need.