Background: Evidence suggests that obesity increases the risk of 13 cancers and data is evolving related to specific dietary risk factors for cancer. Western Australia (WA) has particularly invested in public health messaging about obesity-related lifestyle risk factors for cancer aimed at motivating positive dietary change.
Methods: A web panel provider surveyed Australians aged 18-65 years (Sep 2023) with quotas applied to achieve a nationally representative sample by age-group, gender and state/territory. Data weighting adjusted the sample to population benchmarks. Multivariable logistic regressions used the national sample (N=2,059) for overall analysis; with WA boosted sample (n=669) vs other states/territories combined (n=1,857) for state-level analysis.
Results: WA reported stronger beliefs with respect to factors associated with cancer risk. Compared to other states/territories, WA respondents were significantly more likely to report that vegetable consumption and physical activity (both p<0.01) reduce cancer risk, and an unhealthy diet (p<0.05), alcohol consumption, and a higher body weight (both p<0.01), increase cancer risk (no difference for ultra-processed food consumption). Further, for the national sample, these beliefs were associated with more positive dietary behaviour. Controlling for state differences, reporting the belief that having a higher body weight increases cancer risk was significantly associated with lower sugary drink consumption (p<0.01), while reporting that eating an unhealthy diet increases cancer risk was significantly associated with less frequent fast food consumption (p<0.05). Reporting that eating ultra-processed food increases cancer risk was significantly associated with both reduced fast food and sugary drink consumption (both p<0.05).
Conclusions: Results reflect greater investment in public health messaging in WA and provide support that knowledge of obesity and dietary risk factors for cancer, particularly ultra-processed food, is associated with decreased unhealthy food and drink consumption. Along with campaigns promoting these messages, coordinated efforts at multiple levels are needed to positively influence behavioural change.