THE South African government is proposing to tax sugar-sweetened beverages (SSBs) as part of a strategy to reduce the prevalence of obesity by lowering sugar intake.
Regulators are hoping that consumers will either stop drinking sugary drinks or switch to a healthier alternative. But policy-makers seem to be ignoring all the other sugary products available – and the likelihood that consumers wanting to avoid higher-priced SSBs will switch to these instead.
This likely ‘substitution effect’ must be fully taken into account in projecting the likely real-world impact of the proposed tax. The National Treasury seems to overlooking the number of substitutes available.
The proposed tax – to be levied at the rate of 2.29c per gram of added sugar in SSBs - singles out ‘added caloric sweeteners’ as the culprit to be countered. Beverages that have only natural or intrinsic sugars, such as 100% fruit juices, are not be taxed – even though some of these fruit juices have a higher sugar content than Coca Cola and a host of other SSBs.
In modern societies, a growing proportion of both food and beverages commonly contain added caloric sweeteners. A recent study found, for example, that 75 percent of foods and beverages bought in the United States contain added caloric sweeteners.
In addition, industrialised food processing and modern food science have come together to make a vast range of palatable, low-cost, ultra-processed, and ready-to-consume products available to consumers. Ingredients typically include a combination of highly refined sugars and starches, edible oils extracted from whole foods, processed animal products, sodium, and other additives.
Affordability and wide availability has been achieved via transnational food and drink manufacturing, global branding and marketing strategies, and low-cost ingredients and additives.
SSBs form only a single part of what has become a massive range of ultra-processed products. Ultra-processed products are harmless when consumed in small amounts. However, if they are consumed in large quantities, they seem to diminish the sensitivity of the body’s satiety mechanisms and so promote energy overconsumption.
If SSBs are taxed and their prices then go up, consumers will still have a vast array of calorie-dense substitutes to choose from, which are also likely to be high in sugar and low in dietary fibre – and have little nutritional value. Such products are widely available and ready-to-consume at convenience stores, retail outlets, and fast food chains throughout South Africa.
The proposed tax could encourage consumers to switch to beverages with non-caloric or artificial sweeteners. Perversely, however, this in itself could worsen the obesity epidemic. This seems counter-intuitive, but various studies have found that artificially sweetened beverages cause more weight gain than SSBs. This, it seems, is because repeated exposure to artificial sweeteners trains palate preferences for all things sweet, so keeping calorie intake high.
Informed consumers will know that a balanced diet should contain a range of nutritionally important products that includes fresh and perishable foods along with products that are ‘whole’ or minimally processed. Taxing on an arbitrary selection of beverages will not help to inform consumers and will do little to change nutritional intake.
Policy-makers must take substitution effects into account and realise pushing up the prices of taxed products is unlikely to have any impact on overall sugar consumption. It is even less likely to have any impact on obesity, which has a complex range of causes and cannot be countered in this simplistic way.
* Jasson Urbach is a fellow on sugar tax at the South African Institute of Race Relations.