Earlier this week, Ireland became the latest country to announce a tax on sugary drinks.
Beginning in April, 2018, it will impose a levy of 20 cents a litre on non-alcoholic water-based or juice-based drinks with added sugar content of five grams or more per 100 millilitres. The levy increases to 30 cents a litre if the sugar content exceeds eight grams a litre. Both pure fruit juice and dairy products are exempt because they are deemed to have nutritional value.
Irish Heart called the action "probably the single most important action government can take to tackle Ireland's obesity crisis."
We got another reminder this week of the relentless increase in childhood obesity, with the World Health Organization reporting that rates have increased tenfold in the past 40 years and predicting there will soon be more overweight than underweight children in the world.
In Western countries such as Canada, there is a glimmer of good news: Obesity rates seem to be stabilizing. But 14.7 per cent of boys and 9.9 per cent of girls being obese is nothing to crow about. We need to find ways to reduce those rates.
One obvious way is to get kids to cut back on their consumption of sugary drinks, which currently account for 10 per cent to 15 per cent of daily caloric consumption.
Canadian consumer health groups such as the Heart and Stroke Foundation of Canada, Diabetes Canada and the Canadian Cancer Society are pushing hard for a sugary drink tax as part of a suite of measures that also includes cracking down on marketing unhealthy foods to children.
A report published last year by researchers at the University of Waterloo estimated that a tax on sugary drinks could raise $43.6-billion over 25 years. That's an eye-popping number at first blush, but it works out to about $1.7-billion a year – a modest amount given the extent of the obesity problem.
The principal criticism of a sugary drink tax is that the scope is too narrow. Why should we tax Coke and Gatorade and not Minute Maid and Yop?
And why tax sugary liquids and not sugary solids, such as chocolate bars and pastries? After all, sugar is sugar, and calories are calories.
In the countries that have imposed or promised to impose a sugary drink tax – France, Norway, Mexico, South Africa, Britain, to name a few – the jury is still out on the impact.
We do know that even the threat of a tax pushes manufacturers to change the formulation of drinks and lower the sugar content. That's good for health but reduces tax revenue.
There's some evidence that, if a tax is imposed, die-hard drinkers will simply shift from, say, Pepsi to a generic brand of cola. That doesn't make them any healthier.
It's also hard to judge the impact of the tax because consumer behaviours have been changing for years, with people increasingly eschewing fizzy drinks in favour of other types of sugary beverages. If more people embrace juices and chocolate milk, are we any further ahead?
We also can't ignore that soda taxes are regressive. They disproportionately affect the poor, who would be much better served by subsidies that make healthy foods affordable.
A final point – one that proponents don't like to say out loud – is that if you want a tax to influence behaviour, it has to be a cudgel, not a nudge. In other words, it has to be significant – at least 20 per cent.
Politicians are going to be reluctant to embrace whopping taxes in our current anti-tax environment. The vicious "Can the Tax" campaign in Chicago, which resulted in the sugary drink levy being reversed, is the type of thing that could also give politicians pause; the sugar and soft drink industries are powerful lobbyists and savvy marketers.
The obesity epidemic was not caused by sugary drinks alone. It is the result of an unhealthy environment – one that encourages the consumption of unhealthy foods and discourages physical activity.
Changing that, if it is possible, is going to require a panoply of bold public policies and a profound cultural shift.
We're not going to tax our way out of the obesity epidemic.
But if we are going to embrace a sugary drink tax, it has to be clear that it is only the beginning of a series of measures that aim to change the way we drink and eat.