NZ study reveals concerning diet trends among disadvantaged kids

A ground-breaking study has shed important new light on the diets of our under-5, finding concerning links between junk food and social deprivation – and potential health risks in later life.

The study’s University of Auckland authors say their findings highlight the need for promoting nutrition among mums – but also for Government interventions limiting kids’ exposure to unhealthy food.

While trends have been gradually improving among 4-year-olds, New Zealand has long ranked poorly among developed nations for childhood obesity.

Health data showed one in eight Kiwi children to be obese, with Māori and Pasifika children and those living in deprived neighbourhoods still over-represented.

Yet until now, little has been known about the whole-of-diet quality of our under-5s at a national level.

Drawing on a trove of longitudinal data from the Growing Up in New Zealand study, which has been tracking some 6000 kids, the researchers were able to pinpoint the most common dietary patterns among children at the ages of 9 months, 2 years and 4 and a half years.

“We then examined what were the main maternal sociodemographic and health behaviour predictors of the children’s dietary patterns identified,” said lead author Dr Teresa Gontijo de Castro, of the university’s Department of Nutrition and Dietetics.

The team singled out two patterns that were observed at each age point: diets with a high intake of fruit and vegetables, and those with a high intake of sugar, salt and fat – including white bread and refined cereals.

Study co-author Professor Clare Wall said it was concerning to see the latter pattern present at each point very early in life.

Studies had shown significant links between poor diets early in life and unhealthy body weight later in childhood and adolescence, she said, which in turn raised the risk of chronic disease throughout life.

“This unhealthy dietary pattern has also been shown to keep stable through childhood and adolescence, with the intakes of the foods that represent this pattern increasing with age.”

University of Auckland researcher Clare Wall.

That pattern was also most observed among kids whose mums were most disadvantaged.

Study co-author Dr Amy Lovell said the picture could be improved by narrowing socio-demographic disparities in New Zealand.

That could include Government-led interventions to make healthy diets more affordable and easier to access, while limiting the availability and marketing of junk food to kids.

“New Zealand currently has no Government-led mandatory actions or legislation to improve the healthiness of the food environments and to limit children’s exposure to unhealthy foods,” Lovell said.

In another key finding, the team found links between kids’ diets and those of their mothers during pregnancy.

Children of mums who followed a “health-conscious” diet while pregnant were more likely to have that diet pattern high in fruit and vegetables.

“These findings may be a result of the influence of maternal eating behaviours and food environments on children’s food habits,” de Castro said.

“Role-modelling and the food environment at home is more important in early life, given the higher dependency of children on their mothers.”

Along with targeted health efforts and policy, she said there was a need for better monitoring of kids’ diet quality, describing the current national survey data as “limited and outdated”.

“This is crucial information if New Zealand is to track the impact of interventions and policies on better diet quality in childhood, and the promotion of long-lasting health and wellbeing for the generations to come.”

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.