There are calls for the health star rating system on food packaging to be made mandatory.
A review into how the system has been performing has been released, which recommends it remain voluntary for at least the next four years.
Both the current and the previous government have opted to work with the food industry to encourage improvements in labelling and reduction in sugar and salt content rather than impose requirements.
But Auckland University health researcher Sally McKay told Mike Hosking an opt-in system isn't good enough.
She says only one in five packaged foods in the supermarket has a rating - and the uptake's been very slow.
"A recent research we did revealed only one in five packaged foods in the supermarket have the health start rating, which is why we are calling for it to be mandatory."
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