Junk food tax as a cure for obesity

Researchers say a junk food tax of 20% would affect grocery shopping habits and curb obesity.

I've recently been a sucker for discussions of systemic approaches to addressing obesity, as you can see from my posts on  targeting food deserts and  developing new diet pills . Institutions (at least ones operating on-level) can't prevent people from eating too much or too poorly, but they can introduce clever ways to alter our behavior around food. Such solutions not only raise issues of health, but those of class, morality, and governance as well.

The suggestive mechanism du jour is a junk food tax. University of Oxford researchers reported yesterday on bmj.com that benefits from such a tariff could be seen if junk food is taxed at at least a 20% rate. The reserachers explain:

Health related food taxes could improve health. Existing evidence suggests that taxes are likely to shift consumption in the desired direction, although policy makers need to be wary of changes in other important nutrients. However, the tax would need to be at least 20% to have a significant effect on population health.

They cite a study on the impact of soft drink taxes in a number of U.S. states. The states all had soda taxes at 1-8%, which appeared to be too small of a deterrent to affect population health. The researchers then looked at the results of studies that tried raising taxes in simulated or closed environments. In many of these studies, such taxes had a significant impact on consumer choices. The report states:

For example a 35% tax on sugar sweetened drinks ($0.45 (£0.28; €0.34) per drink) in a canteen led to a 26% decline in sales.

The the third part of the report looked at modelling for economic impacts on health. Here's where they got that 20% value. Apparently that's the tax on sugary drinks needed to reduce obesity in the U.S. The authors comment that such a tax would have a weaker effect in the UK, but mainly because of less soft drink consumption there to begin with. They found models of the effect of such taxes on unhealthy food items less conclusive.

The Oxford researchers acknowledge that such a tax would be regressive in that it would have a disproportionate impact on the poor, a point which similar prior arguments failed to address. But, they add:

Progressive health gains are expected because poor people consume less healthy food and have a higher incidence of most diet related diseases, notably cardiovascular disease. Consequently the absolute reduction in disease incidence would be greater among poorer groups, assuming similar dietary changes. Moreover there is some evidence that those who are poorer are more sensitive to price changes and so would experience greater dietary improvements.

That still sounds like a values judgement to me, I would like to see further research into such inequities.

But, even if more academic evidence emerges in support of the efficacy of junk food taxes, larger hurdles lie ahead of tax implementation. There's the matter of convincing the public to accept so-called "nanny state" policies, and, there's the powerful soft drink lobby to battle. For example, in 2010 Washington State lawmakers instituted a soda and candy tax. It was voted down just six month later by the state's citizens, through an initiative funded with $16 million from the American Beverage Association.

Photo:  Lauren Mitchell/Flickr

This post was originally published on Smartplanet.com