The nation's peak doctors' body has renewed its call for a ban on junk food advertising targeting the young, after research has confirmed how easily they are persuaded.
Australian Medical Association (AMA) national president Dr Andrew Pesce said the AMA has for years been calling for a ban on broadcast advertising of energy-dense and nutrient-poor foods and beverages to children, particularly in children's television viewing times.
"As a community we must help young people make the right choices about the foods they eat, and this will help to reduce levels of overweight and obesity among young Australians," Dr Pesce said in a statement on Wednesday.
"The findings from this survey highlight the impact of advertising and marketing on adolescents and reinforces the AMA's concerns ... about the marketing of unhealthy products to children and young people."
The study, the most comprehensive investigation of the health of the nation's secondary school students since 1985, took in 12,000 students from across almost 240 schools.
Dr Pesce said the survey, commissioned by the Cancer Council and the National Heart Foundation, showed that advertising and marketing had a direct influence on students' food choices.
It found one in four were overweight or obese, while more than half indicated they had tried a new food or drink product in the past month because they had seen it advertised.
A quarter said they had eaten at a fast food outlet because it had a special offer or giveaway with a meal, while almost 20 per cent opted for a food or drink because it was linked to a movie or sports personality.
"These results clearly show that the problem of targeted marketing of junk food to children and young people is not limited to broadcast advertising," Dr Pesce said, "with non-broadcast food-marketing techniques such as freebies and gimmicks also having an impact on food choices."
He said high rates of obesity among young people would lead directly to a greater risk of chronic cardiovascular disease later in life, and he echoed the Cancer Council's stated concern that young people today may lead shorter lives than their parents' generation.
"All governments must focus on improving the health of young people now and prevent the situation where, for the first time in Australia, we may potentially face a generation of children who will live shorter lives than their parents," Dr Pesce said.
The Australian Food and Grocery Council (AFGC) has introduced a Responsible Children's Marketing Initiative (RCMI), which signs up participating food companies to a code designed to curb the deliberate targeting of children in advertising.
Despite this, the RCMI's first report released in January found one in five of the food and drink ads aired during children's television programs was still for products high in sugar, fat or salt.