A 20 per cent tax on fizzy drinks would save about 67 lives a year, a new study says.
Researchers at the National Institute for Health Innovation at Auckland University, aided by Otago University, estimate such a tax would reduce energy consumption by 20 kilojoules a day, or 0.2 per cent.
This would be enough to help avert about 67 deaths from cardiovascular disease, diabetes and diet-related cancers a year, according to the study, published in the New Zealand Medical Journal on Friday.
Lead researcher Professor Cliona Ni Mhurchu says 17 per cent of total sugar intake among adults comes from non-alcoholic drinks.
This number rises to 27-29 per cent for people aged 15 to 18, and it's 24 per cent for children aged five to 14.
"Randomised controlled trial data have shown convincingly that reducing consumption of sugar-sweetened beverages decreases weight gain in children," Prof Ni Mhurchu said.
Prof Ni Mhurchu said high sugar intakes were linked to obesity, type 2 diabetes and cardiovascular disease, meaning there was a strong case for efforts to be made to reduce consumption.
Co-author Professor Tony Blakely, of Otago University's Wellington branch, said a 20 per cent tax could generate up to $NZ40 million ($A37.24 million) in taxes if applied to all fizzy drinks, or $NZ30 million if applied only to sugar-sweetened varieties.
He arrived at the figure after finding the average household spent $NZ166, or 1.8 per cent of their food expenditure, on fizzy drinks a year.
A review of international evidence suggested taxes on fizzy drinks would improve diets and health, he said.