The report, which was commissioned by the ACT government last year and focused on children aged up to 14 years, highlighted "the need for urgent action to protect the health of Canberra's next generation".

Heart Foundation ACT chief executive Tony Stubbs said the audit showed children were exposed to an enormous amount of unhealthy advertising, despite childhood obesity being one of the most serious health problems in the territory.

The report found 86 per cent of adverts in sporting venues featured unhealthy food and drink items, compared to 80 per cent in shopping centres and 77 per cent in supermarkets.

Up to 95 per cent of adverts assessed in Canberra's two major hospitals promoted unhealthy food or drink items.

Nearly three-quarters of adverts within 200 metres of ACT schools featured products not recommended for sale in school canteens.

Close to half of the sporting organisations assessed by the audit received sponsorship from companies selling unhealthy products, whether that be cash contributions, uniforms, equipment, or vouchers.

Mr Stubbs said the report was evidence of an environment where it was impossible for parents to shield their children from junk and fast food marketing.

"Even when children join their local sports organisations or go to sports venues, they cannot escape it," he said.

"We need to fix this marketing imbalance to better support the work parents, schools and governments are doing to improve our children's health."

Minister for Health Simon Corbell said the audit highlighted the widespread marketing of unhealthy food and drinks to children.

"This report shows there is work to be done across the board to reduce the impact that unhealthy food and beverage promotions have, and to achieve a real impact on the health of our children," he said.

"Its findings provide the ACT government with an important snapshot of the current food and beverage marketing environment operating in Canberra."

The audit found food and drink companies had begun seeing children and adolescents as consumers capable of lobbying their parents to purchase products on their behalf.

'This increased interest from marketers is due to children's ability to make their own purchasing decisions, impact the purchasing decisions of their parents, and develop brand recognition, preference and loyalty as they grow into adult consumers," the report said.

"The positioning of unhealthy foods and beverages within easy reach and sight of children can encourage pester power, by targeting children and encouraging them to pester their parents to buy the products for them."

The report, which will be used as the basis for public consultation later this year, found marketing was damaging the health objectives of the ACT government.

"The current landscape of food and beverage marketing in the ACT promotes a diet that is contrary to the recommendations contained in the Australian Dietary Guidelines," the audit said.

"Rather than supporting children to limit these foods and beverages, marketing is enticing them to consume ever greater quantities as part of their daily diets."

Mr Corbell said the report showed there was work to be done across the board to reduce the impact of unhealthy food and beverage promotion.

"We know being overweight or obese is a serious health issue that can increase the risk of chronic diseases, and data from 2011-12 showed that approximately one quarter of children aged 5-17 years were overweight or obese in the ACT.," he said.

"The Heart Foundation's report provides an excellent starting point for further consultation to occur with the Canberra community, food retailers, and other industry stakeholders on this important issue."

Mr Stubbs said children did not have experience or the ability to understand the marketing was designed to change their opinions or behaviours.

"The danger is that unhealthy food and beverage marketing is not only negatively influencing our children now, but it is setting them up with poor dietary habits, preferences and health that they will carry over into adulthood," Mr Stubbs said.

"There is no one solution to obesity. It requires the input of government, the food industry, the community and individuals to work together."