Fat shaming people into losing weight has the reverse effect and makes them more likely to have a heart attack, according to new research.

The idea that fat shaming - the term used to describe mocking a person for their size - inspires victims to shed the pounds is a myth, scientists have warned.

Researchers said painful messages drive people towards comfort eating and may increase the risk of cardiovascular and metabolic disease.

Professor Rebecca Pearl, of the University of Pennsylvania, said: "There is a common misconception that stigma might help motivate individuals with obesity to lose weight and improve their health.

"We are finding it has quite the opposite effect. When people feel shamed because of their weight, they are more likely to avoid exercise and consume more calories to cope with this stress.

"In this study, we identified a significant relationship between the internalisation of weight bias and having a diagnosis of metabolic syndrome, which is a marker of poor health."

Her research branded 'body shaming' as a "pervasive form of prejudice" which is found in cyber bullying, critiques of celebrities' appearances, at work and school and in public places.

People who are battling obesity face being stereotyped as lazy, incompetent, unattractive, lacking willpower and to blame for their shape.