Public health advocates are calling for action to curb obesity after fewer Australian children were found to be eating fruit and vegetables.

The number of children eating the recommended amount of fruit has dropped substantially, according to the results of the Australian Bureau of Statistics' National Health Survey.

This was down by nine per cent (73 per cent to 64 per cent) in the five years to 2022.

Just one in 20 children ate the recommended daily serve of vegetables.

The proportion of children who did not eat vegetables every day tripled from 1.5 per cent in 2011-12 to 4.5 per cent in 2022.

Over the same period, the proportion of children who did not eat fruit daily doubled to almost six per cent.

Jane Martin, the executive manager of the Food for Health Alliance that comprises Cancer Council Victoria, Deakin University and VicHealth, was concerned by the results.

She put the blame on the marketing of processed foods and sugary drinks.

"The food industry spends millions of dollars every year bombarding Australian children with unhealthy food marketing as they watch TV, go online and use social media," she said.

"While this boosts the industry's bottom line, it puts children's health at risk and is clearly having a detrimental effect."

She called for a levy to be introduced on sugary drinks and for the Albanese government to fund and implement the National Obesity Strategy.

The federal government last year introduced the 10-year strategy to prevent, reduce and treat obesity.

Federal Health Minister Mark Butler said the first step was to work with states and territories.

"We are doing this work now," he said.

He said this was helping to identify priority areas for preventing obesity and treatment policies.

The strategy has targets that include reducing the number of overweight and obese children by at least five per cent by 2030.

Peak health groups including the Australian Medical Association have backed calls for a tax on sugary drinks.

The survey found the proportion of overweight or obese adults had increased by three per cent over the past decade to almost 66 per cent.

More than a quarter of Australian children are overweight or obese.