Associate professor Felice Jacka was in Warrnambool last week to provide an overview of evidence from around the world which demonstrated the important role diet played in mental health problems in children, adolescents and adults.

Some of her recent research found that older Australians with unhealthy diets have smaller hippocampi - a part of the brain believed to be integral to learning, memory and mental health. "Junk food may actually shrink parts of your brain,” she said.

Working with Norwegian collaborators, Dr Jacka showed, for the first time, that a clear relationship existed between mums’ diets during pregnancy and children’s mental health.

This research also showed that children with unhealthy diets over the first few years of life had increased symptoms of depression and anxiety, as well as aggression and tantrums.

“We’ve known for some time that very early life nutrition, including the nutrition received while the child is in utero, is related to physical health outcomes in children – their risk for later heart disease or diabetes for example,” Dr Jacka said. “But this was the first study indicating that diet may also be important to mental health outcomes in children.” 

Dr Jacka said junk food needed to be treated the same way smoking had been. She said there needed to be policy change by governments and called for taxation on processed and sugary foods, limits on fast food outlets’ proximity to schools and other public policy changes.

Dr Jacka said eating a poor diet, such as processed and sugary foods, was normalised and the food was very addictive. “It needs to no longer be seen as socially acceptable,” she said. “Similar to the way smoking is viewed today.” 

Dr Jacka said the quality of a person’s diet was more important than if they were overweight and people could have a good quality diet and be overweight and vice versa.