There is intense debate in the US concerning proposals to legally limit the cup size of soft drink portions sold in New York, down from 48oz to a mere 16oz – the “soda ban”. The issue is now heading for the appeal court, and Mayor Bloomberg explains the proposals well in this short video:
A recent study by the University of California , “Regulating the Way to Obesity: Unintended Consequences of Limiting Sugary Drink Sizes”, has been embraced by soft drinks manufacturers (SoDM), since it appears to show that by limiting portion sizes, consumers in the study finish up by drinking even more of the fizzy because of the ‘bundling’ effect.
This appears to be over-compensation by consumers – they end up drinking more combined smaller portions than the (unavailable) larger portion size they desire. The industry claims that this proves that if the soda ban became law, the unintended consequence of this would be increased consumption rather than the decrease the legislators anticipated.
Manna from heaven, it seems, for Big Sugar in their battle for the hearts, minds and pancreases of obese diabetics everywhere (and they are everywhere). And so, beginning on the very day of publication, the California study has been blogged, tweeted, facebooked and generally flogged mercilessly to support SoDM defence against the soda ban.
Take the trouble to read the actual report however, rather than those heady headline conclusions, then matters are much less straightforward. It turns out to be a study of consumer behaviour when a choice is withdrawn. The study centres on what individuals do when they can’t get their sugar ‘fix’ in the desired dosage, in this case a 32oz cup of fizzy from Macdonalds – 22 tsp of sugar! . And guess what? Just like a heroin addict when his regular supply is interrupted, he scouts around and gets all the little bags he can accumulate, paying little regard to arithmetic, and very often concludes matters with an overdose.
One must assume that 32oz (and 48oz) portion sizes were not promoted as a means of reducing sales of soft drinks, so it appears odd that a major plank of the soda ban defence is now “the larger the cup, the less we sup”. Never mind, at least it is evidence-based! But is it reasonable for Big Sugar to use the study conclusions to support resistance to the soda ban?
If evidence such as this is to be used to guide health policies, then the consequences of withdrawing a product need to be measured against the consequences of keeping it, and continually promoting the product to both existing and new consumers. In other words: Exactly which is the ‘lesser of two evils’? The study did not (and could not) answer these questions, but these answers are crucial to the debate and policy formulation.
What the report conclusions might have been had they included a control group unaware that a 32oz Gulp existed prior to the trial, we will probably never know – it is doubtful such a group could ever be found, or the study get ethical approval. However, since every big-gulper began his habit with smaller doses, it is fair conjecture to assume the study would have shown a degree of progression towards the 32oz dream prize, showing increased consumption in the process, and that big sizes lead to big appetites. Hardly the ideal corporate defence against Bloomberg’s soda ban.
The study seems a tidy effort, although it is unclear who paid for the soft drinks consumed by the subjects – and its structure closely mimics the proposals of Bloomberg. The wisdom of promoting a report which so closely links consumption of soft drinks to obesity in the report title itself may soon dawn on the marketing people at SoDM, but until then carry on tweeting!