The research, funded by the Australian Research Council Discovery Grant Scheme, is the first of its kind in Australia. 141 obese Australians were extensively interviewed to try to gauge how they perceived their weight and ability to manage it.

Co-author and Head of Monash University's Consumer Health Research Group (CHaRGe) Dr Samantha Thomas said those in the severely obese category with a Body Mass Index (BMI) of more than 40, blamed themselves for their weight and often described themselves as at war with their bodies.

"Severely obese individuals felt an urgent and desperate need to change their health behaviours, but felt completely powerless to do so. Most felt worried and scared about the potential health consequences of their weight. Most felt blamed and ashamed by public health and education campaigns about obesity, which did little to actually help them address their weight," Dr Thomas said.

Dr Thomas said in contrast, people whose weight fell within the mild to moderately obese range understood they were significantly overweight but did not believe they needed to lose weight to improve their health and wellbeing.

"Those individuals, with a BMI between 30 and 40, believed they could lose weight if they needed to, but did not feel this was an urgent health priority as most felt physically healthy," Dr Thomas said.

"Most of the study participants in this category deliberately sought to distance themselves from public health messages about obesity and the word obesity because of the social stigma attached to the condition. They also stigmatised those who were fatter than themselves."

Dr Thomas said it appeared the public health messages were not getting through to those who needed it most.

"The campaigns don't seem to be having much of an effect. Those in the mild-moderately obese category said their weight creates feelings of social isolation or discrimination, yet don't fully understand the health risks associated with the extra kilos," Dr Thomas.

"In contrast, people with a significant weight issue realised they were at an extremely high risk of disease but didn't feel they could change. Further confirmation that the stigma and social stereotyping associated with obesity - including from government campaigns - is vastly impacting on individuals' beliefs and behaviours.

"Society's attitudes need to change, governments need to refocus health messages and we need to accept obesity as a serious health issue that addresses a person's well-being not just the added kilos."

In Australia it is estimated that about 18 per cent of adults are obese according to their body mass index (BMI 30+). Of these, about two per cent are considered severely obese (BMI 40+). Whilst those who are severely obese comprise only a small proportion of the obese population, both international and Australian studies show that the prevalence of severe obesity is increasing at nearly twice the rate of obesity overall.