In a comment piece in the i newspaper yesterday, Julia Hartley-Brewer made a plea for a tax on fatty foods and sugary drinks. She was clear about what needed to be done: 'Forget about a few pence on a litre of cola or a cheeseburger and fries, though. We need obesity taxes at 50 or 100 per cent to hike up the cost of the foods and drinks we should only be consuming as an occasional treat, not as part of our daily diet.'
Is this true? Would a tax work at all? A study of 'heath related food taxes' from Oxford University was supportive, though the results were based largely on modelling and controlled trials, as the first real health-related food tax in Denmark has not been running long enough to provide anything other than anecdotal evidence.
One specific piece of evidence comes from Ireland, where a 10% soft drinks tax, introduced in the 70s, intended to bring in revenue rather than improve health, saw an estimated 11% drop in consumption. Because of this, the report recommends a 20% tax on sweetened drinks (though interestingly not on sugary drinks like smoothies, which can contain more sugar than a cola). They also suggested putting VAT on unhealthy foods like chocolate biscuits, confectionary and soft drinks.
It seems likely that there would be some impact, but one cause for suspicion about the level of benefit is that there is already, in a sense, an 'unhealthy foods' tax if you compare the price of typical single chocolate bar with, say, a banana, which addresses many of the same desires for sweetness, is equally filling and is significantly healthier. The chocolate bar has the equivalent of a 4-500% price hike on the banana... and yet we still know which many of us pick up from choice.