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Could a sugar tax help combat obesity?

BMJ 2015; 351 doi: (Published 29 July 2015) Cite this as: BMJ 2015;351:h4047
  1. Sirpa Sarlio-Lähteenkorva, adjunct professor, ministerial adviser, Ministry of Social Affairs and Health, Finland,
  2. J T Winkler, emeritus professor of nutrition policy, London Metropolitan University, UK
  1. Correspondence to: S Sarlio-Lähteenkorva sirpa.sarlio-lahteenkorva{at}, J T Winkler jtw{at}

Sirpa Sarlio-Lähteenkorva says that a specific tax on sugar would reduce consumption, but Jack Winkler thinks that such taxes are politically unpalatable and would have to be enormous to have any effect

Yes—Sirpa Sarlio-Lähteenkorva

Taxes are traditionally regarded as a source of revenue, but they can also be used as tools in health policy. Indeed, taxes on alcohol and tobacco have been widely used for decades and reduce consumption.1 2 Many countries have also recently passed legislation to introduce or increase taxes on specific food items such as soft drinks, sweets, chocolate, ice cream, or other unhealthy foods, often aiming to combine fiscal and health benefits.3 Although data are limited, emerging evidence indicates that food taxes can influence consumption.4 5 6

However, improving dietary habits this way is more complicated than limiting alcohol or tobacco use. Food is a necessity, and overall consumption is relatively insensitive to price changes. When some foods become more expensive consumers tend to look for cheaper substitutes. These cross elastics of demand need to be considered carefully when planning food taxes. It has been suggested that to influence consumption the price increase has to be at least 20%,4 and consumption of some foods is less sensitive to price changes than for others. Limited data come mostly from modelling studies. However, increasing evidence suggests that taxes on soft drinks, sugar, and snacks can change diets and improve health, especially in lower socioeconomic groups, where price elasticity is high.5 The potential for improved health is greatest when combined with incentives for choosing healthier foods.5

Health and other benefits

Taxes such as excise duties on specific food categories that are common constituents of poor diets are practicable because they are simple to administer. And it is possible to target the most problematic foods, such as sugary soft drinks, …

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