Sugar, sugar: has taxing drinks reduced our waistlines?

In August 2018, the UK followed a number of other countries by introducing a ‘sugar tax’ on sweetened drinks. But why was it considered necessary, and just how effective has it been? 

7 minutes

  • The background to introducing the sugar tax
  • How much are drinks being taxed?
  • What might be the next moves?

The nation’s ever-expanding waistlines have long been a cause for concern. According to a 2016 report by NHS Digital, 26% of men and 27% of women in England were deemed obese while a further 40% of men and 30% of women were overweight. Some 2% of men and 4% of women were considered morbidly obese - with a Body Mass Index exceeding 40 [1].

Alarmingly, the problem starts early: again, according to the same report, one in five children aged 10-11 are classified as obese, along with one in ten aged 4-5.

Being overweight has causal links to a number of serious health conditions – including heart disease, cancer, strokes and diabetes. According to since 1996, the number of people diagnosed in the UK has risen from 1.4 million to 3.5 million. Taking into account those likely to be living with undiagnosed diabetes, the number with diabetes in the UK is now over four million – and estimated to rise to five million by 2025.

Why were soft drinks singled out?

While, for many years, the fat in our diet has shouldered much of the blame for rising obesity, excess sugar is now seen as the primary reason. The culprit? The Government itself states that “soft drinks are… the biggest source of sugar in children’s diets”.

To put this into context: NHS advice is that adults should consume no more than 30g of free sugars a day, and children aged 7 to 10 no more than 24g [2]. But just one 330m can of Coca Cola contains 35gm of sugar, and one 250 ml can of Red Bull packs 27g.

And that’s why – after an extended (often heated) public debate about state interference in people’s dietary choices - the UK Government eventually immersed its toe in the water with a ‘sugar tax’ as part of its childhood obesity strategy.

Officially termed the Soft Drinks Industry Levy (SDIL), the tax levies 24p on drinks containing 8g of sugar per 100ml, and 18p a litre on those with 5-8g of sugar per 100ml. 

While raising money was not pitched as a main objective, it was originally estimated that the Government would raise around £500 million a year in the process (to be spent on school sports and breakfast clubs). Their stated main aim was to encourage soft drinks manufacturers to avoid the levy by voluntarily reducing the sugar in their drinks – and that has certainly happened, as the tax take has halved from the original estimate.


Was it the right thing to do?

Sophie Medlin, a leading dietitian and director of CityDietitians, says “Many experts argue that there are far bigger dietary problems to tackle and that sugar is only a small piece of the puzzle - which is fair. However, it’s important that the government takes action on the food industry… and targeting sugar is an easy win.

“Sugar undoubtedly contributes to some of our worse dietary habits because it is non-nutritive energy… it provides lots of energy but no other nutrients. An apple has around two teaspoons of fruit sugar (fructose) but you also get fibre, vitamins and antioxidants.” 

Just what can we learn from other countries’ experiences? France introduced a sugar tax of 6p a litre in 2012 – resulting in a reduced consumption of soft drinks and a marked rise in bottled water. Mexico saw a brief reduction in sales, but after consumers decided they could live with the relatively small price rise, sales bounced back.

The evidence around the world varies considerably – but the ways in which the tax has been levied vary too, so too the amounts.

Ahead of the tax levy, research was carried out at a local leisure centre, led by Sheffield University’s Professor Liddy Goyde. Her conclusion was that: “Centre users bought more low sugar drinks when a 20p price difference was introduced. It also showed that the biggest differences were in sales of the drinks marketed for children, suggesting that parents responded to the ‘win-win’ of the cheaper option being the healthier option for their children, but that adults buying for themselves were more likely to stick to their usual choice… despite the price change.”

The biggest challenge is that other items in our diet contain large amounts of free sugar – including many savoury products… and we are only 12 months into tackling a societal issue that might take many years to turn around.  “Unfortunately,” concludes Sophie Medlin, “any health benefits will take longer to reach measurable levels.” 

Arguably to make a real difference, it will take more manufacturers to reformulate their drinks: while many have decided to reduce the sugar content rather than risk losing sales (including the makers of Fanta, Ribena, Irn-Bru and Lucozade) some very big names (such as Coke Classic and Original Pepsi) feel sufficiently confident that customers will pay extra rather than switch brands.

Is this likely to be the last throw of the sugar dice?

Helen Dickens, Assistant Director or Campaigns and Mobilisation at Diabetes UK is a big supporter of sugar tax and says that: “It is estimated that the levy could prevent obesity in up to 140,000 adults and children each year and, as a result, nearly 19,000 cases of Type 2 diabetes. Since the introduction of the levy a number of soft drinks have been reformulated, and we look forward to seeing its continued impact.

“But it is just one measure and not enough on its own. In order to tackle obesity and the rise in Type 2 diabetes in the UK, we need concerted action across society.”


[1] NHS Digital, 2018. Statistics on Obesity, Physical Activity and Diet.

[2] NHS, 2017. How does sugar in our diet affect our health?