Junk food is harming kids’ mental health

Families with unhealthy diets have worse mental health and wellbeing than those who mostly avoid meals packed with sugar, fat and salt.

A world-first, Melbourne-led study is the first to show that children’s psychological* health is not immune to what they eat.

The effects of high-inflammatory* diets are putting kids on a path to poor mental health from as young as age 11.

The evidence is now well established that inflammation* in the body – be it chronic* or low-level inflammation that bubbles away and may not cause symptoms – is actually damaging cells and organs gradually and leading to many chronic diseases such as diabetes*, cancers and heart disease. Causes of this chronic immune response can be diet, stress, obesity and pollutants*.

The Murdoch Children’s Research Institute (MCRI) looked at the diets and self-reported mental wellbeing of more than 1800 Australian parents and their 11-12 year-old children, as well as measuring markers of chronic inflammation in their blood.

The study, published today in the British Journal of Nutrition, showed the benefits of healthy eating – namely anti-inflammatory diets high in fruit, vegetables and whole grains – extended beyond physical health, and that families can eat their way to good mental health.

A child’s weight was not an influencing factor. Regardless of size, the negative impacts of inflammatory diets high in processed foods affected children across the board.

Researchers said the results suggest that diet may directly affect mental health through mechanisms* such as influencing gut bacteria, changes in brain plasticity* or hormone* regulation.

Lead researcher at the MCRI, Dr Kate Lycett said while research had shown that specific anti-inflammatory diets could reduce depression symptoms in adults, until now little was known about the impact on children and how a typical family diet – a mix of both inflammatory and anti-inflammatory foods – impacted psychological wellbeing.

“What surprised me was we saw the same results in terms of the risk in children and parents,” Dr Lycett said.

“That’s really important, because as adults we try to regulate what we eat. We know when we eat a packet of chips we feel awful, but we often don’t think about that when we give our kids those chips.

“We know that (in) our dietary patterns and mental health, the pathways for those are set early in life.”

Dr Lycett said the findings, “provided further compelling* evidence” that more policy changes were needed around junk food advertising, price and access, to make healthy foods the easy choice for families.

“We need to stop putting the blame on families about diet,” she said.

“I feel really strongly that as a society we need to recognise that what we’re doing isn’t working and we need policy-level interventions*.

“When you go to your local pool, they’ve got hotdogs and sugar-sweetened beverages … we allow this fatty food to be right at children’s eye level.

“We really need to get serious as a society about trying to tackle this.”