OVERWEIGHT women may never escape the stigma of obesity even after they have lost weight, according to researchers.

The study by the University of Hawaii, the University of Manchester, and Monash University, Melbourne, Australia, examined whether anti-fat prejudice against women persisted even after they had lost significant weight and were thin.

The researchers asked young men and women to read vignettes describing a woman who had either lost 70 pounds or had remained weight stable, and who was either currently obese or currently thin. Participants were then asked their opinions about this woman on a number of attributes, such as how attractive they found her and their overall dislike for fat people.

The team found that participants in the study - published in the journal Obesity - expressed greater bias against obese people after reading about women who had lost weight than after reading about women who had remained weight stable, regardless of whether the weight-stable woman was thin or obese.

"We were surprised to find that currently thin women were viewed differently depending on their weight history," said Dr Janet Latner, 'study lead' at the University of Hawaii.

"Those who had been obese in the past were perceived as less attractive than those who had always been thin, despite having identical height and weight."

One of the more disturbing findings from the study, the researchers said, was that negative attitudes towards obese people increase when participants are told that body weight is easily controllable.

Co-author, Dr Kerry O'Brien, from the University of Manchester's School of Psychological Sciences, said: "The message we often hear from society is that weight is highly controllable, but the best science in the obesity field at the moment suggests that one's physiology and genetics, as well as the food environment, are the really big players in one's weight status and weight loss.

"Weight status actually appears rather uncontrollable, regardless of one's will-power, knowledge and dedication. Yet many people who are perceived as "fat" are struggling in vain to lose weight in order to escape this painful social stigma. We need to rethink our approaches to, and views of, weight and obesity."

The findings, say the authors, demonstrate that residual obesity stigma persists against individuals who have ever been obese, even when they have lost substantial amounts of weight. Obesity stigma is so powerful and enduring that it appears to even outlast the obesity itself.

Dr Latner added: "Descriptions of weight loss, such as those often promoted on television, may significantly worsen obesity stigma. Believing that obese people can easily lose weight may make individuals blame and dislike obese people more.

"The findings demonstrate that residual obesity stigma persists against individuals who have ever been obese, even when they have lost substantial amounts of weight. Obesity stigma is so powerful and enduring that it may even outlast the obesity itself.

"Given the great number of people who may be negatively affected by this prejudice, obesity discrimination clearly needs to be reduced on a societal level."