Here's why lying to doctors is common

If you tend to stretch the truth while answering your doctor on questions related to exercise or diet, you have company.

Some people lie to their doctors to avoid being judged, while others feel simply too embarrassed to tell the truth or just do not want to be lectured about how bad certain behaviours are, suggests new research.

"Most people want their doctor to think highly of them," said the study's senior author Angela Fagerlin from University of Utah in the US.

"They're worried about being pigeonholed as someone who doesn't make good decisions," she added.

Insights into the doctor-patient relationship came from an online survey of two populations.

One survey captured responses from 2,011 participants who averaged 36 years old. The second was administered to 2,499 participants who were 61 on average.

About 60 to 80 per cent of people surveyed were not forthcoming with their doctors about information that could be relevant to their health, according to the study published online in the journal JAMA Network Open.

Besides fibbing about diet and exercise, more than a third of respondents did not speak up when they disagreed with their doctor's recommendation. Another common scenario was failing to admit they did not understand their clinician's instructions.

In both surveys, people who identified themselves as female, were younger, and self-reported as being in poor health were more likely to report having failed to disclose medically relevant information to their clinician.

The trouble with a patient's dishonesty is that doctors cannot offer accurate medical advice when they don't have all the facts.

"If patients are withholding information about what they're eating, or whether they are taking their medication, it can have significant implications for their health.

Especially if they have a chronic illness," said the study's first author Andrea Gurmankin Levy, Associate Professor at Middlesex Community College in Middletown, Connecticut, US.