Full-sugar soft drinks being sold at same price or cheaper than sugar-free versions, study finds

The authors said it was evident customers were not being charged extra for high-sugar drinks in supermarkets despite the introduction of the sugar tax.

Full-sugar soft drinks are being sold at the same price or even cheaper than their sugar-free alternatives despite the imposition of a sugar tax, a new study has found.

The Sugar Sweetened Beverage Tax (SSBT) was introduced in 2018 with the aim of encouraging consumers to make healthier choices. However, it has emerged customers are not being charged extra for high-sugar drinks in many supermarkets.

Research by academics at the School of Medicine at the University of Limerick and the Technological University of the Shannon examined the relatives prices of popular carbonated drinks and their sugar-free versions in 14 retail outlets.

They found Coca-Cola, Pepsi, and various Club products were being offered at the same price as their sugar-free versions in about 60% of cases, and the sugar-free drink was even more expensive than the standard beverage in six instances.

In cases where the price of a full-sugar version of a drink was higher than the sugar-free version, the researchers found the price difference was sometimes less than the sugar tax rate, meaning the tax is not being passed on to consumers.

The tax that was introduced in 2018 imposes a 5c levy on 330ml cans, an 8c levy on 500ml bottles, and 16c levy on litre bottles where a drink’s sugar content exceeds 5g per 100ml.

Where the sugar content exceeds 8g per 100ml, the levy rises to 8c on a 330ml can, 12c on a 500ml bottle, and 24c on a litre bottle. The tax was extended to include plant protein drinks and beverages containing milk fats in 2019.

The study, which was published in the Irish Journal of Medical Science this week, noted manufacturers had reformulated some drinks to lower their sugar content below 5g per 100ml with a view to avoiding the sugar tax. 

These included Fanta, 7Up, and Sprite.

It examined the prices of 452 full-sugar and sugar-free carbonated beverages in 14 supermarkets, ranging in size from 150ml cans to two-litre bottles, and including various multipack bundles.

In 42% of supermarkets, cans of Coca-Cola and Diet Coke were the same price. Even where the full-sugar version was more expensive, it was sometimes lower than the 5c SSBT levy.

Larger bottles were “routinely” sold at the same price, the study found. The Club products surveyed as part of the research were Club Orange, Club Lemon and Club Rock Shandy, along with their zero-sugar versions.

The authors said it was evident customers were not being charged extra for high-sugar drinks in supermarkets despite the introduction of the sugar tax.

“Such a lack of price differentiation clearly undermines the effectiveness of the SSBT in influencing consumers choices,” they added.

The study said increasing the sugar tax to ensure outlets pass the tax on to consumers was a possible option, and ringfencing revenue for health expenditure might make such a move more politically acceptable.

It said the move by some manufacturers to reformulate their products and reduce their sugar content should be seen as a success for the tax.