Under the system, launched in December, food products are scored between half a star and five stars according to their energy, fat, sugar, and salt content.
So far, supermarket giants Coles and Woolworths have the stars on their private labels while some Sanitarium, Nestle, Uncle Tobys, and Lion products also display them.
However, Choice said a number of companies, including US multinational Kellogg’s, were refusing to take part.
“Food manufacturers have been on notice since June last year to implement the new health star scheme however iconic brands such as Kelloggs, McCain and Mars are still refusing to serve up the information consumers need,” Choice spokesman, Tom Godfrey, said on Tuesday.
“It’s just not good enough that a major player like Kelloggs, that sells popular brands Just Right, Special K, Coco Pops, and Nutri-Grain, are withholding basic health information and that’s why we have launched this campaign.”
“Kellogg’s should be embracing the new system and celebrating the fact that Just Right and All Bran receive 4 and 5 stars respectively. On the flip side, Australians deserve to know that Nutri-Grain and Coco Pops get 2 and 1.5 stars respectively.”
He said the labelling system cut through “marketing hype” and made it easier for consumers to make healthier choices.
“Consumers are often barraged with an array of confusing claims when shopping. For example, a product claiming ‘low in fat’ may have high sugar content.
“Australians shouldn’t have to take a calculator to the supermarket to figure out if their food is healthy. The health star rating makes this simple, cutting through the marketing hype and delivering at a glance the information you need to make healthier choices.”
In a statement, Kellogg’s said the company offered cereals with “different nutrition profiles so that consumers can choose options that suit their individual needs and wants”.
A spokeswoman said Kellogg’s was “always seeking ways to improve the nutrition of our products”.
“As a company we are looking at a number of ways to reduce sugar in our portfolio,” she said.
Health groups have been calling for the voluntary system to be made mandatory, and say most Australians support making it compulsory to help battle obesity.
Australia has one of the highest rates of obesity in the world with 63 per cent of adults and one in four children being overweight or obese.
The Federal Government developed the star rating system with state and territory governments, the New Zealand government, as well as industry, public health and consumer groups.