All around the world a fierce debate is raging about whether food manufacturers should be required to display a symbol on a food label that would indicate to consumers, at a glance, whether food is healthy or not.
It's hard to work out why something so simple and useful could cause so much friction, and escalate into a fully fledged food war.
On one side of the debate is the food industry, which wants to use food labels as a marketing tool and is opposed to anything on a label that could put people off purchasing their food.
On the other side are health professionals and food campaigners, who want something simple and easy to understand on a label, such as a colour-coded "traffic light" symbol, that would make it easy for consumers to choose healthy food.
Traffic light labels were originally developed by the United Kingdom Food Standards Agency to help consumers decipher complex nutrition information and work out whether food is healthy or not.
Food that is high in fat, sugar or salt gets a red dot, while food that is low in sugar, fat or salt gets a green dot. If it is somewhere in between, it gets an orange dot.
When the European Union tried to make traffic light labels mandatory, the European food industry spent $36 million lobbying to defeat it. Similar battles have taken place in Canada and the United States to defeat mandatory traffic light labelling.
Closer to home, and under the radar, a battle is raging about whether Australia and New Zealand should introduce some sort of traffic light labelling system here.
Last year the Australian and New Zealand governments agreed to develop a simple, interpretive front-of-pack labelling system to help Australasian consumers work out whether food is healthy or not.
They noted that the debate about traffic light labelling had been "divisive" and "polarised", so they agreed to set up a "collaborative process" to work out a way of improving nutrition labelling, "without saddling New Zealand businesses and households with extra costs".
Front-of-pack labelling advisory groups were appointed in both countries, to advise what sort of front-of-pack labelling system to support, and both governments agreed they would make a final decision in December.
But whereas the Australian Government has conducted an open consultation process, our Government's deliberations have been shrouded in secrecy.
Behind the scenes, however, public health and consumer groups are pushing for traffic light labelling, because research shows that it is simple and easy for consumers to understand.
But the food industry remains implacably opposed to traffic light labelling. The last thing they want to see is a red dot on their food, because that would put consumers off purchasing it.
The industry argues that traffic lights would arbitrarily penalise some healthy foods such as milk and nuts that are relatively high in fat - and reward drinks like diet Coke that contain no sugar.
No one wants a system that makes Coke Zero look healthy, and milk and nuts unhealthy. Fortunately, the food company Sanitarium has come up with a compromise, which takes into account healthy ingredients such as fibre, as well as unhealthy ingredients like added sugar. It would give food an overall rating and enable consumers to easily identify healthy as well as unhealthy ingredients in food.
Instead of pushing this version, however, the industry has been lobbying for a percentage daily intake system, which is complex and difficult for consumers to understand without getting out a calculator to tally up the percentages.
Another proposal is for a star rating system, which would rate food, and give it a star, depending on how healthy it was judged to be.
As the debate drags on, I fear the two governments won't make a decision in December, as they promised to do. In the face of fierce food industry resistance, I predict they will kick for touch and come out with some vague, voluntary system that won't help consumers choose healthy food.
This would be unfortunate, to say the least, because if we want to tackle our epidemics of obesity and type 2 diabetes, we need to make it easier for consumers to make healthy eating choices.
We need to put public health ahead of the profits of the industry, in other words. But a Government that has thrown out almost every healthy eating initiative in New Zealand, including healthy food in schools, is unlikely to do that. That's probably why it's dragging its feet on traffic light labelling and is apparently much more reluctant than Australia to introduce an effective system.
Former Green MP Sue Kedgley is a safe food campaigner