Medical experts who signed the letter include epidemiologists Alistair Woodward and Rod Jackson, paediatrician Diana Lennon, researcher Peter Davis - husband of former PM Helen Clark - cardiologist Harvey White, nutritionist Jim Mann and public health specialist Sally Casswell.
The group's spokesman, Boyd Swinburn of the University of Auckland's School of Population Health, said the Government, led by Health Minister Jonathan Coleman, had a golden opportunity to prove it was serious about tackling the problem.
"In a couple of weeks the Health Minister will be at the World Health Assembly in Geneva and what will be put on the table for endorsement is a report from the WHA commission on ending childhood obesity," Professor Swinburn told the Weekend Herald.
"That commission is being co-chaired by Sir Peter Gluckman, the Prime Minister's chief science advisor. New Zealand has had a big hand and shown leadership in steering that report, not only with Sir Peter, but Helen Clark was also involved.
"The second recommendation is a tax on sugary drinks and at the assembly ministers from around the world will be called upon to support the report and its recommendations.
"We would like to see that reflected in New Zealand and serious notice taken."
The UK tax, from 2018, could add 8p (17c) to the price of cans of fizzy drinks such as Coca-Cola and 7Up, energy drinks like Red Bull and even cartoned juice. Celebrity chef Jamie Oliver has celebrated the British Government's decision and called upon New Zealand to follow suit.
Dr Coleman said this month that the Government had no plans for a similar measure here. But Professor Swinburn said a couple of game-changers were the published evaluation of the tax impact in Mexico which came out earlier this year and the UK reviewing all the evidence and choosing to tax sugary drinks.
"Those important new pieces of information add impetus to having a tax in New Zealand."
Dr Coleman said his position on NZ sugar taxes remained unchanged.
He said he was keeping an eye on two major studies which looked at international evidence supporting the effectiveness of sugar tax - one from North Carolina and one from Waikato University - which were due out at the end of next year.
Despite what the letter said, Dr Coleman did not agree that there was more evidence supporting the effectiveness of a tax on sugary drinks than the 22 strategies in the Government's existing plan to combat obesity in kids.
A Herald poll last month suggested an overwhelming public desire to introduce a sugar tax, with more than 80% of 11,700 voters in favour of new legislation.
