Health organisations say most people do not understand daily kilojoule counts and are wrong when asked to estimate their daily needs.

A survey by the Heart Foundation and Cancer Council SA has found 60 per cent of people noticed kilojoule labelling, 23 per cent thought they knew their personal daily needs but just 4 per cent had an accurate view.

The South Australian Government introduced mandatory kilojoule labelling of products sold by fast food outlets in 2012 in an effort to tackle obesity.

Wendy Keech of the Heart Foundation thinks a consumer education campaign is needed to help people understand how the numbers can help them tackle weight issues.

“People don’t actually understand how many kilojoules they should be consuming in a day,” she said.

“Unless we can get the information to them, the information on the menu boards is irrelevant.

“We must get information to people about what their daily needs are, general information is important so people understand the ball park they should be in.”