The report, to be published on Monday, also shows that 30 per cent of two- to 15-year-olds do not eat the recommended daily serve of fruit.

A second survey, on substance use among high school students, reports consumption of alcohol fell from 64.5 per cent of high school students in 2008 to 48.5 per cent in 2011.

The first report, on the health status of ACT children, shows one-fifth of the territory's population at June 2012 was aged between two and 15.

The proportion had increased by 2.5 per cent since 2011, the second-highest proportional increase over one year in the country.

The survey found 97 per cent of Canberra households and cars were smoke-free and 90 per cent of parents rated their children's health as good or excellent.

It also found ACT children ate fewer fried-potato products. The figure fell from 56 per cent in 2007 to 48 per cent in 2010.

But the same survey warns of sedentary habits among Canberra children, with 46 per cent spending more than two hours a day on electronic media and only 23 per cent spending one or more hours on physical activity outside school.

The data also shows just 40 per cent of ACT children are getting the recommended daily serve of vegetables, while 70 per cent are eating the recommended serving of fruit.

The report found younger children were ''significantly more likely to eat the recommended daily serves of fruit and vegetables than older children.''

Chief Minister Katy Gallagher said on Sunday that although the report contained good news on the health of ACT children, there was room for improvement.

The government published a plan last month to tackle the ACT's rising obesity levels.

It includes a proposal for mandatory junk food-free checkouts at supermarkets and for regulation of the sale of sugary drinks.

According to the survey, 11.1 per cent of children ate no confectionery, but 32.9 per cent consumed it three or more times a week.

The report is likely to fuel the government's motivation for a clampdown on sugary drinks, showing that 20 per cent of children have six or more cups a week.

Fifty-one per cent of children were reported to consume no sugary drinks.

''We pride ourselves on being the healthiest place in Australia, with longer life expectancy, lower rates of major illness and more active and healthier lifestyles than other jurisdictions,'' Ms Gallagher said. ''But it is important that we continue to track our progress and constantly seek to do [more].''

A second survey on substance use by secondary students found that smoking rates in 2011 were below the national average, with 19.1 per cent of students reporting having smoked, compared to a national figure of 23.3 per cent.

The percentage of Canberra students reporting they had used an illicit drug was 12.7 per cent, below the national average of 15.6 per cent.

Use of illicit drugs had also fallen among territory high school students since 2008, when 14.8 per cent reported having used them.