Obese Australians are being stared at, portrayed as lazy and over-indulgent or receiving negative comments on a daily basis, a study has found.

University of NSW researchers gave 46 obese adults a digital device on which to record details of each weight bias experience over a two-week period.

On average, the participants experienced 11 episodes of weight stigma in the fortnight - almost one episode a day.

One individual encountered stigma 11 times in a single day.

Stigma was most often expressed by strangers.

Given that 63 per cent of adults are overweight or obese, fat-based stigma could potentially affect millions of Australians.

It can lead to lower self-esteem, depression and increased body dissatisfaction, says study author Dr Lenny Vartanian, a psychologist at UNSW.

"Research shows that obese people who feel frequently stigmatised are less motivated to diet and exercise and more likely to binge eat."

"Our analysis of the contextual factors indicated that stigma experiences arise from a range of sources - including strangers, spouses, friends, parents, and the media, and are also common both at home and in public."

The researchers define weight stigma as any episode where a person feels they are being treated differently because of their size.

This could include being stared at, receiving a negative comment or being exposed to portrayals of overweight people as lazy or over-indulgent on TV or in magazines.

The results appear in the Journal of Contextual Behavioural Science.