Following a recent call to impose a 20% sugar tax to subsidise the cost of fruit and vegetables, the ongoing debate over potential positives and negatives of a sugar taxes took another turn this week when Sirpa Sarlio-Lähteenkorva, adviser at the Ministry of Social Affairs and Health in Finland and Jack Winkler, emeritus professor of nutrition policy at London Metropolitan University argued their respective cases for and against such a levy in the BMJ.
Professor Sarlio-Lähteenkorva suggested that a specific tax on sugar would reduce consumption – suggesting there is “increasing evidence suggests that taxes on soft drinks, sugar, and snacks can change diets and improve health, especially in lower socioeconomic groups.”
However, Professor Winkler warned that while a sugar levy would be a positive development ‘in principle’; such taxes are politically unpalatable and would have to be enormous to have any effect.
Indeed, he warned that taxes on foods are not just a political hot potato, but are also economically ineffective – adding that recent research suggested a 10% tax would reduce consumption by ‘less than a sip’ while a 20% tax would reduce energy intake by just 4 calories per day.
"Effects of this size will not reverse global obesity," he argued.
Sarlio-Lähteenkorva noted that taxes can only be a partial solution, suggesting that a sugar tax on all products may be more acceptable than just one on certain categories "because it would treat all sources equally.”
“It could also stimulate reformulated products, with less sugar and hence liable for less tax,” she suggested.
However, Winkler suggests creating incentives for healthier foods, and cutting product margins on sugar-free soft drinks would be a positive alternative which would make the healthy choice the cheaper choice – and could boost companies' profit.
He also noted that while advocates of a sugar tax assume that such any levy would be reflected fully in retail prices, the fact is that in many countries, market forces mean that companies absorb part, or all, of cost increases.
Winkler warned against making comparisons between sugary food and drinks and tobacco taxes that have successfully driven down smoking - noting that ‘a sense of scale is required.’
“Tobacco taxes are often cited as a precedent for such disincentives to consumption … Tobacco taxes vary worldwide, but not in the 10-20% range. The UK rate is 348%,” he said.
Winkler also pointed out that before and after the recent UK election, government spokespeople stated repeatedly that there will be no new food taxes and immediately rejected recent proposals for a 20% tax.
“Why are we still debating this idea?” he asked. "Nutrition policy needs price instruments, but a more positive selection. Sugar taxes are unlikely to be adopted and would not make much difference anyway.”
"We need fiscal policies that take health seriously," argued Sarlio-Lähteenkorva. "Sugary foods and sugar sweetened beverages are associated with weight gain. Governments must tackle the related adverse health effects, such as diabetes, coronary heart disease, and hypertension.”
“A tax on sugar, preferably with measures that target also saturated fat and salt, and incentives for healthy eating, would help," she concluded.