Obesity may soon overtake smoking as the number one risk for cancer if Australians don't start eating more fruit and vegetables and reduce their alcohol consumption, an expert has warned.
People often associate poor diet with obesity and type 2 diabetes but not cancer, says University of Sydney Professor of Dietetics Margaret Allman-Farinelli.
The professor says actually obesity changes the hormonal environment in the body and increases inflammation, increasing a person's risk of cancer.
"Obesity may take over from smoking as the number one risk for cancer, with a lack of fruit and vegetables, wholegrains, exercise and increased alcohol consumption to blame," Professor Allman-Farinelli said.
"We know choosing the wrong diet is what can lead to increased risk of developing bowel cancer."
Also, women who gain weight after menopause are much more likely to get post-menopausal breast cancer, and obesity increases the risk of cancer of the oseophagus, she said.
"That increased weight around the abdomen can push the contents of the stomach back onto the lower part of the organ and that leads to something called Barrett's Oesophagus which makes people more prone to develop cancer."
A good diet is not about maintaining a particular body type or a particular body image, it's about health, says Professor Allman-Farinelli.
"We are talking about it because we know that its the second modifiable risk factor after smoking that can prevent you from getting cardiovascular disease, being overweight, type 2 diabetes and a whole range of cancers."
Despite the association between a poor diet and disease, Prof Allman-Farinelli fears little progress has been made through the current public health messaging. She says the national health surveys show the quality of Australians' diet has not improved.
"We are sadly falling behind the recommendations," said Prof Allman-Farinelli.
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In 2014-15, Australian Bureau of Statistics data showed less than half of all adults met the guidelines for the recommended daily intake of fruit - two or more serves.
Just seven per cent met the guidelines for serves of vegetables - five to six per day.
Only one in twenty adults met both guidelines. These rates were similar to 2011-12. Women were more likely to meet the guidelines than men.
Despite women performing slightly better on the fruit and vegetable front, there is concern more are drinking unhealthy levels of alcohol.
Prof Allman-Farinelli says analysis of the data shows middle age and older women are drinking more wine compared to their mother's and grandmother's.
"The message is we need to eat more vegetables, more fruits, more wholegrains and cut down on those highly processed, palatable foods for better diet to prevent disease."
But it's not just the individual's responsibility to improve diet, Prof Allman-Farinelli acknowledged.
Food reformulation and the types of foods provided to people at institutions, businesses and workplaces, such as universities, are important changes that need to happen, Prof Allman-Farinelli says.
"We have to look at employers, the food industry, the government, everyone to make a concerted effort."
