His is a government that has strongly resisted introducing new taxes or lifting existing ones – except those aimed at backpackers.

And if the Coalition needed further grounds for opposing the introduction of a sin tax, one suspects its pro-business, libertarian wing would be happy to oblige. Yet the Grattan Institute's report recommending an excise of 40¢ for every 100 grams of sugar on non-alcoholic beverages is compelling and persuasive.

Nearly two-thirds of Australians are now classified as overweight or obese. The rate among children is one in four. Potential complications from overweight and obesity cost the health system about $500 million annually.

The number of people with a high body mass index (related to overweight and obesity) was negligible in the 1980s. But it's grown rapidly since then to be the second highest contributor to the national burden of disease.

For governments to try to reduce it by taxing one of its most significant contributors – non-alcoholic drinks incredibly high in sugar – would seem sensible and prudent.

Indeed, many countries have already done so, including Britain. It's still too early to conclude what impact these taxes have had. In Mexico consumption is climbing two years after a roughly 10 per cent tax was imposed on sugary drinks. That tends to undermine predictions of doom that soft drink manufacturers raise against such taxes.

Their other argument – that the poorest in society are hit hardest by sugar taxes – is harder to counter. Yet, governments readily impose ever-greater rates of excise on the tobacco and alcohol that low-income earners consume to minimise and offset the harmful health effects. That is the nub of the Grattan Institute's argument.

Sugar is added to a dizzying array of food, frequently to excess, and it might be argued that taxing only soft drinks would be a symbolic gesture. But few foods are as packed with sugar and empty calories.

If governments are serious about wanting to fight overweight and obesity, sugary drinks are an appropriate place to start.

There are plenty of healthier alternatives, and most soft drinks could easily be reconstituted to contain less sugar without consumers even noticing.