That means more than half the population is likely to experience health problems such as diabetes, high blood pressure and cholesterol and back and joint pain due to excessive weight.

Health statistics for residents have alarmed medical professionals.

Exercise physiologist Andrew Zorzit said a combination of factors, including the socioeconomic mix and multicultural population in Mount Druitt and St Marys, affected the area's poor health.

"A lot of people are very uneducated about exercise and nutrition," he said.

"Especially people who speak English as a second language. There is an understanding out there that a healthy diet is beneficial to losing weight but there is a lack of knowledge about what that actually is. And economics is a big thing; cheap, fast food is easy." Mr Zorzit is optimistic people want to get healthier.

The personal trainer of almost 25 years' experience said more GPs were prescribing exercise as a remedy to health problems.

Mr Zorzit also believes one of the health industry's enemies — television — was encouraging people to lose weight.

"I think TV shows showing people who are overweight training have helped," he said.