People who seek medical advice about weight loss have hugely different outcomes depending on how their doctor addresses the matter – and how sympathetic they feel their doctor to be.

New research from Duke University in the US found that when doctors gave generic advice, such as “you should exercise more”, participants in the study only achieved modest weight loss. However, when they gave very specific advice and instructions for lifestyle change, results were significantly better.

The year-long study followed 134 overweight people – predominantly women and with a mean age of 51. Some had additional health issues such as diabetes.

Participants were invited to take part in a weight-loss programme that included tailored behavioural goals, educational material, calls from coaches and text messages with weight-loss tips and progress reports. They also saw health care providers regularly.

Some doctors urged patients in general terms to "lose weight" or "exercise more,” while others gave specific advice, such as encouraging them to take calls from weight-loss coaches. These patients lost nearly 7lbs more on average.

In addition, people who rated their doctor as empathetic and caring also lost 7lbs more on average.

"Patients who enrol in a weight-loss programme should consider asking their health care providers to check in on their progress, as this can keep them accountable” said Megan McVay, assistant professor at the University of Florida, and co-author of the study. “It’s also important to have a doctor they feel cares about them and has sympathy towards how hard it is to lose weight."

"Just telling somebody to lose weight or improve their diet or physical activity didn't work," said study co-author Gary Bennett, professor of psychology at Duke. “Doctors should encourage patients to get involved in specific programmes.”

The study has been published in the Journal of General Internal Medicine.