Study results back effectiveness of sugary-drinks tax

The case for a sugary drinks tax is made by a new study showing that overseas, a 10% tax sparked a 10% drop in consumption, researchers say.

''We'd recommend this as a great next step for the New Zealand government,'' said Dr Andrea Teng, lead author of the University of Otago study.

Health Minister David Clark has said he also wants healthier drinks but wants to work with industry to bring in voluntary sugar reductions.

Dr Teng, of Otago University's Wellington campus, said New Zealand had ''very high rates of obesity''.

Asked if the Government should seriously consider introducing a sugar tax, she said ''for sure''.

''I think it's important that our Government is quite serious about child obesity, considering the [New Zealand] obesity epidemic,'' she said.

''This new review presents compelling evidence that sugary drink taxes result in decreased sales, purchasing or dietary intake of taxed beverages.

''For a 10% tax, sugary drink volumes declined by an average of 10%.

''It shows taxes on sugary drinks are an effective tool to reduce consumption, and we know from other research that the high consumption of sugary drinks increases the risk of obesity, diabetes and dental caries.''

The evidence emerging from the Otago University meta-analysis - a summary analysis of earlier international studies - was ''really clear'', she said.

Review co-author Amanda Jones said a tax could also prompt manufacturers to ''reformulate sugar levels downward, as seen in the UK, even before their tax was introduced in April 2018''.

The Ministry of Health says New Zealand has the third-highest adult obesity rate in the OECD, behind only the United States and Mexico, and ''our rates are rising''.

The Wellington campus researchers combined evidence from settings where a sugary drinks tax had been applied and evaluated it.

Studies included four cities in the US: Cleveland, Ohio; Portland, Maine; Berkeley, California; and Philadelphia, Pennsylvania.

A regional tax was studied in Catalonia, Spain, and the effects of country-wide taxes were studied in Chile, France and Mexico. The research was published in international scientific journal Obesity Reviews.

Dr Teng said successive New Zealand governments appeared to have little interest in introducing sugary-drink taxes.

But it was ''probably inevitable'' that this type of tax, which was highly targeted at protecting child health, ''will need to be seriously considered by New Zealand politicians''.

john.gibb@odt.co.nz