A national cross-sectional survey of 500 primary care physicians in the US finds their weight may influence obesity diagnosis and care. Among the findings, published earlier this month in the journal Obesity, is the suggestion that doctors whose BMI is in the normal weight range are more likely to to discuss weight loss with patients than overweight or obese colleagues.

Lead author, Dr Sara Bleich, an assistant professor in the Department of Health Policy and Management at Johns Hopkins Bloomberg School of Public Health, told the press their findings also suggest that normal weight physicians “have greater confidence in their ability to provide diet and exercise counseling and perceive their weight loss advice as trustworthy when compared to overweight or obese physicians”.

For their survey, Bleich and colleagues assessed the impact of physician BMI on obesity care, their confidence in their ability to give advice on diet and exercise, perceptions of role modeling and perceptions of patient trust in weight loss advice. All the data came from questionnaires that the doctors completed themselves.

BMI, or body mass index, is the ratio of a person’s weight in kilos to their square of their height in metres. They classed doctors who reported themselves as having a BMI of 25 kg/m2 or over as overweight or obese, and under that to be of normal weight.

When they analyzed the results, the researchers found that:

  • Physicians who reported having normal BMI were more likely to discuss weight loss with their obese patients than physicians who reported having BMI in the overweight or obese range (30% versus 18%, P=0.010).
  • Physicians with normal BMI had more confidence in their ability to give advice on diet (53% vs 37%, P=0.002) and exercise (56% vs 38%) to their obese patients than their overweight or obese counterparts.
  • More of the normal weight physicians thought overweight or obese patients would be less likely to trust weight loss advice if it came from a doctor who was overweight or obese (80% of normal weight doctors thought this compared to 69% of their overweight or obese colleagues, P=0.02).
  • Doctors who reported having normal BMI were more likely than their overweight or obese colleagues to believe that physicians should be role models to their patients by keeping to a healthy weight (72% vs 56%, P=0.002) and doing exercise regularly (73% vs 57%, P=0.001).
  • The chances of a doctor diagnosing a patient as obese (93% vs 7%, P < 0.001) or starting a conversation about weight loss (89% vs 11%, P ≤ 0.001) was higher when they judged the patient's BMI to be the same or more than their own.

In contrast, the researchers found that obese doctors had more confidence in prescribing medication for weight loss, and were more likely to report success in helping patients lose weight.

They conclude that:

“These results suggest that more normal weight physicians provided recommended obesity care to their patients and felt confident doing so.”

However, they said while the results suggest obesity practices and beliefs appear to vary according to doctors’ BMI, more research is needed before we can fully understand the impact of physician BMI on obesity care.

Bleich said perhaps we could help doctors increase their confidence in providing care for their obese patients, regardless of their own BMI, by helping them improve their own health and increasing the quality of the obesity-related training they receive.

The National Heart, Lung and Blood Institute and the Health Resources and Services Administration helped pay for the study.

The US Centers for Disease Control and Prevention (CDC) estimate that more than one-third of US adults are obese, and this costs the nation around $147 billion annually in related health care.

Being obese increases a person’s chance of developing many chronic diseases, including type 2 diabetes, heart disease, stroke and high blood pressure.

Although guidelines exist for physicians to counsel and treat obese patients, previous studies have found only a third of such patients report receiving either a diagnosis or advice about weight loss from their doctors.

Written by Catharine Paddock PhD