Public health experts want Australia's food and drink health star ratings to become mandatory.

Australian shoppers have embraced the nutrition guides, but they are only being displayed on around 30 per cent of foods.

Most of these products have scored at the upper end of the five-star scale.

And public health experts are concerned some producers are "gaming the system" by exploiting loopholes around sugar, salt and fat content.

The federal government has commissioned an independent five year review into the health star ratings, which is due next month.

The George Institute for Global Health is concerned the dietary guidelines are skewed towards the interests of food companies.

The institute wants Australia to learn from Canada and France, where labels are required to be a uniform position, size and colour to enhance visibility for consumers.

It also wants the algorithm improved to incorporate added sugars, increase penalties on salt content, and remove undue benefits from protein.

Kathryn Backholer, from the Public Health Association of Australia, said the voluntary health star rating system was not working for consumers.

"Too few products have a health star rating and those that do, tend to be at the healthier end," she told AAP.

"We anticipate that the newly re-elected Morrison Government will want to improve the Health Star Rating system further to assist everyone to make better choices when they do buy packaged food."