"The issue of sugary drinks intake is urgent, considering our high rates of dental health problems as well as child and adult obesity and diabetes," health researcher Dr Gerhard Sundborn said.
"A sugary drinks tax is the most effective means to address this, and only the Government can enact it. It requires the Government to provide leadership which prioritises our children's health over corporate profits."
But the tax won't be implemented any time soon.
Health Minister Jonathan Coleman said the Government's position on a sugar tax hadn't changed.
"It's not something we're actively considering. We are continuing to keep a watching brief on the emerging evidence and practice."
He said that despite what advocates claimed, there was no evidence that a sugar tax decreases obesity rates.
"There's no single solution that will fix obesity. We've implemented a Childhood Obesity Plan with a range of interventions across Government, the private sector, communities, schools and families.
"We're now one of the few OECD countries to have a target and comprehensive plan on childhood obesity."
More than 1.3 million Kiwis are obese, making New Zealand the third-fattest country in the OECD.
In Mexico, where Coca-Cola is almost as much a part of the culture as tequila and more than 70 per cent of the population is overweight, a sugary drinks tax has been in place for two years.
Though adding just one peso (7c) to the cost of a can of soft drink, consumption has fallen by an average of 7.6 per cent. Purchases of untaxed drinks went up by 2 per cent over the period, although there was a decline in the second year.
It is still too early to tell whether there have been any health benefits to the Mexican population.
Despite broad support for a tax from the Greens, the Maori Party and the Opportunities Party at a Fizz Symposium of health professionals and researchers in June, the Government has declined all invitations to attend for more than four years.
Labour is preparing its own sugar tax policy.
"In contrast, when Coke have invited the Government to their functions they find the time," Sundborn said, citing visits by then-Prime Minister John Key and Gerry Brownlee to a new Coca-Cola Amatil factory in 2011, and by Minister for Economic Development Stephen Joyce in 2016.
A spokeswoman for Coleman said parliamentary commitments in Wellington meant he wasn't able to attend the Fizz Symposium.
"He did pass on his apologies and wished the organisers the best wishes for a successful event. Attempts were made to find a suitable fill in, but the timing of the event made it difficult.
"Simon O'Connor wasn't able to as he already had commitments with the Health Select Committee he chairs."
A tax on drinks with more than 5g per 100ml was announced by the UK Government last year, and is due to come into effect in April 2018.
Other countries to have introduced a similar tax include Hungary, where a 2011 tax led to a decline of around a fifth in sales, Tonga, the Cook Islands, France and several cities in the US, including several cities in the San Francisco area, Seattle, Boulder, and Philadelphia.
Denmark abolished its eight-decades old sugar tax in 2014, citing large tax losses from illegal sales, as Danes were jumping the border into Sweden or Germany to purchase drinks in bulk.
