The Mitchell Institute claims more than 42 per cent of people are obese in parts of regional NSW, three times the rate compared to in wealthy inner Sydney.

A Wagga dietician said the conversation around weight is changing, as services acknowledge the issue is caused by outside factors, not just a person's habits.

The research from the Institute at Victoria University shows 71.1 per cent of adults in the Wagga Local Government Area are obese or overweight in the 2014/15 financial year.

It also reveals that 23.6 per cent of youth are overweight or obese. In the LGA, 37.8 per cent of adults and 7.9 per cent of youth are obese.

Acting health promotion manager for Murrumbidgee Local Health District, Jackie Priestly, said changes are being made to reframe the conversation.

"We are raising the issues of environment, it is not just about personal habits so the fact that plate sizes are bigger, and there are increased outlets for fast food," she said.

"All of this is having an impact over a period of time.

"MLHD is working with lots of different community groups and organisations to bring about change, and it is certainly a high priority for us."

Ms Priestly added that 64.2 per cent of adults were above a healthy weight range in the MLHD in 2018.

"We know it is a risk factor for other illnesses such as diabetes," she said.

"One of our goals is to increase the number no of referral to the Get Healthy Service so we are informing adults about that.

"We are also working with school canteens to assist them in updating their menu."

Rosemary Calder from the Mitchell Institute at Victoria University said wealthier areas had lower rates of obesity with more space dedicated to parks, gardens and recreational facilities.

She added people in such areas could often to exercise to work, and said policy change was needed at every government level.

"We have spent too long as a nation expecting individuals to be able to change their behaviour to reduce their weight," Professor Calder said.

"However, the evidence is very clear that this has little chance of success without a very strong focus on the environmental factors in the places where we live that contribute to poor nutrition and inactivity."

Professor Calder said places with the highest rates of obesity also have much higher rates of smoking, inactivity and chronic illness.

"Local governments are critical to local planning and the creation of healthy and active spaces for their residents," she said.

"However, they are often hampered by lack of funding and regulatory power."

Residents can access the Get Healthy Coaching service on 1300 806 258.