The health star rating for 100-per-cent no-added-sugar juices has been cut.

The Australian and New Zealand Ministerial Forum on Food Regulation is undertaking a five-year health star rating system (HSR) review.

The HSR system gives products a rating from half a star to five stars, depending on their nutrients.

The trans-Tasman forum voted to lower the health star rating of fresh, pure juice on Friday.

It will see some products knocked down from five-start status to as little as two stars. In some cases, fruit juices will be considered no healthier than diet carbonated sodas.

Agriculture Minister David Littleproud has been campaigning against the downgrade, saying the entire HSR system could be undermined by the decision.

“What I don't accept is the insanity of this decision, which really has no basis on nutritional value — it really just is mind-numbingly dumb,” he said.

The fruit juice industry has been rocked by the decision.

Citrus Australia chief executive Nathan Hancock says it was based on inaccurate beliefs about sugar, and does not acknowledge the other nutrients in fruit juice.  

“The message that they've been giving us is that they want people to drink more water, because it's better for hydration, and they want to take sugar out of the diet,” he told the ABC.

“Because diet soft drinks have artificial sugars, it elevates them above juices which have natural sugars.

“The desire to stamp sugar out of the consumers' diet has been misconstrued and taken off in a different direction.

“There's so many other products consumers are eating these days, unwittingly eating sugar — it's added sugar, it's not naturally in the product.”

He said some producers are likely to stop using the HSR system on their products.