Jun 04, 2013 10:49 PM EDT By Staff Reporter, UniversityHerald Reporter

When it comes to taking diet advice from a physician-size matters. This is according to a new study led by a team of researchers at the Johns Hopkins Bloomberg School of Public Health and the Johns Hopkins University School of Medicine who examined the impact of primary care physician BMI (body mass index) on their patients' trust and perceptions of weight-related stigma. They found that overweight and obese patients trust weight-related counseling from overweight physicians more than normal weight physicians and patients seeing an obese primary care physician were more likely to perceive weight-related stigma. The results are featured online in the June 2013 issue of Preventive Medicine.

"With respect to overall trust, our results suggest that overweight and obese patients trust their primary care physicians, regardless of their body weight," said Sara Bleich, PhD, associate professor with the Bloomberg School's Department of Health Policy and Management. "However, with respect to trust in weight-related advice, we found that patients more strongly trusted diet advice from overweight primary care physicians as compared to normal BMI primary care physicians. In addition, we found that patient perceptions of weight-related stigma increased with physician BMI. Patients seeing obese primary care physicians, as compared to normal BMI physicians, were significantly more likely to report feeling judged because of their weight."

Using a national cross-section survey of 600 overweight and obese patients, researchers examined overall trust and trust in weight-related counseling from their primary care physicians. Overall trust was assessed by asking, "Using any number from 0 to 10, where 0 means that you do not trust this doctor at all and 10 means that you trust this doctor completely, what number would you use to rate how much you trust this doctor?" While, trust in weight-related advice was assessed by the survey question: "How much do you trust the advice from this doctor about how to control your weight; improve your diet or increase your physical activity, a great deal; a good amount; only some or very little?" Bleich and colleagues conducted multivariate regression analyses to determine whether trust or perceived stigma differed by physician BMI.

"While weight-related stigma has been documented among health professionals for decades, as well as lower physician respect towards patients with a higher BMI, our finding that weight-related stigma increases with physician BMI was quite surprising," notes Bleich. "Recent changes to obesity coverage among the publicly insured makes understanding primary care physicians' barriers to providing effective obesity care critical. Existing research suggests that primary care physicians face numerous challenges to providing optimal obesity care which include knowledge deficits, negative attitudes and structural barriers. Future research should further examine the impact of physician BMI on obesity care. In particular, why patient-perceived physician stigma is higher among heavier primary care physicians and why the patterns we observed between physician BMI and trust in weight-related counseling differ by the type of counseling."

See Now: Covert Team Inside Newsweek Revealed as Key Players in False Human Trafficking Lawsuit