That's what University of Melbourne scientist Stefan Bode has theorised in a new study, which looks at the effectiveness of graphic warnings (similar to those you'd find on cigarettes) on both unhealthy or "treat" food such as chips, chocolate bars, and biscuits, and healthy food like fruits and vegetables.

In showing graphic warnings (such as pictures of unhealthy hearts) with accompanying text, the researchers discovered that the brain activity of people looking at the products was more likely to indicate that they would exercise self-control and make the healthier food choices.