Gastric banding and other weight-loss procedures are being increasingly accepted in the medical community as useful treatments for obese patients suffering from chronic health conditions. But the procedure is mostly performed in private hospitals and a study co-authored by Australian National University researcher Rosemary Korda has confirmed it is mostly performed on patients who earn more than $70,000 a year.

Using data from the 45 and Up Study of more than 250,000 NSW men and women, the researchers concluded that people on higher incomes were five times more likely than other Australians to undergo bariatric surgery.

While the procedure was subsidised by Medicare, many patients still faced several thousand dollars of out-of pocket costs.

''Essentially people can only access it if they have private health insurance and can afford the out-of-pocket costs.

''It's that mismatch between what's being done in the private and what's being done in the public system,'' Dr Korda said.

While it was not without risk, bariatric surgery could have positive outcomes for people at risk of, or suffering from, chronic health problems, including type 2 diabetes, and those with morbid or severe obesity who had not been able to lose weight through other means.

''For quite a large proportion of the population with obesity it is quite difficult to lose weight or if you can, to actually maintain the weight loss.

''There are a lot of reasons for that and some of them are physiological.''

Dr Korda said consideration needed to be given to how resources could be allocated to ensure people on lower incomes could access bariatric surgery.

''We need to have a conversation about services. Obviously we don't have unlimited resources for these things but I think it is important to start addressing these issues about the distribution of the resources,'' she said.

The research was published in the Medical Journal of Australia.

During the ACT election campaign, Chief Minister Katy Gallagher promised a re-elected Labor government would commit extra resources to bariatric procedures in public hospitals.