University of Auckland researchers say industry self-regulation is failing to keep the cap on sugar with sugar-laden drinks accounting for almost 80 percent of drinks sold at supermarkets.
Over half the drinks the researchers monitored had between six to 12 teaspoons of sugar per drink - more than an adult should consume in a single day.
Dr Sally Mackay from Auckland University co-led the study and told Morning Report flavoured milk, orange juice and soft drinks were all included in the study.
While over time there's been an increase in lower sugar drinks available, MacKay says the market is still dominated by sugary drinks.
"We do believe that we do need some government regulation and something like the UK soft drinks levy which has been shown to reduce the sugar consumption and also the amount of sugar in the drinks in the UK."
She said self-regulation doesn't bring about much change.
Studies have shown a reasonably high levy of 20 percent of the consumer price is needed for it to be successful, she said.
But would the tax hit lower income earners the hardest? MacKay says soft drinks aren't a necessary part of a food budget.
"We do find that people living in more deprived neighbourhoods are more likely to have softdrinks and so they're also the ones that tend to be at high risk of obesity and dental care so I think the trade-off is in the improvement in their health."