Sugar tax study: compelling evidence to carry out 'fascinating experiment in public health policy'

By David Burrows

- Last updated on GMT

© iStock/elenachaykina
© iStock/elenachaykina
Overweight and obese children tend to drink more sugar-sweetened drinks than those of normal weight, making a “compelling case” for taxing the beverages, according to researchers in Ireland.

 "The introduction of a tax on sugar-sweetened drinks in combination with other public health interventions has the potential to have a measurable effect on the scale of the epidemic of childhood obesity,”​ explained Dr Janas Harrington from the HRB Centre for health and diet research at University College Cork.

The Irish Government – like others in Europe​ – will introduce a sugary drinks tax next year, as part ofa national plan to tackle obesity​. But will it be effective?

Fuelling obesity

Dr Harrington and her team decided to find out. They assessed data from 1,075 children aged between eight and eleven, using three-day food diaries to determine how many sugar-sweetened drinks (SSDs) they were consuming.

They then dug deeper into the 724 children whose reported energy intake was in the normal range, so-called “plausible energy reporters”.​ Almost one in five of this group (18%) were overweight or obese, against one in four (25%) of the total sample.

The majority (82%) of the children guzzled one standard can (328ml) of SSDs a day. However, average intake volumes were “substantially higher”​ in children who were overweight or obese compared to normal weight children (383ml per day for overweight/obese children and 315ml per day for normal weight children).  The team also noted a “clear trend of decreasing body mass index with falling soft drink consumption”.

SSDs contributed to an average of 6% total calorie intake and almost a quarter (22%) of total sugar intake. Average calories from SSDs also increased incrementally between weight categories: SSDs contributed 108 kcal for normal weight children and 155kcal for overweight or obese children, equating to 5.8% and 7.6% of total daily calories respectively.

Further analyses showed that (after adjusting for gender, parental education, physical activity and TV viewing), those who drank more than half a normal can of SSD per day (more 200ml) were “twice as likely”​ to be overweight or obese than those who drank less than half a can per day (less than 200ml).

Fascinating experiment

Dr Harrington, who was presenting the results of her study at the European Congress on Obesity in Portugal recently, said the levy wouldn’t curb obesity overnight. But given high levels of consumption and the lack of nutritional value in SSDs, there is a “compelling case”​ for the policy.

“This will be afascinating experiment in public health policy,” ​she said of the government’s plans to introduce a levy next year.

When announcing the SSD tax in the October 2016 budget, Ireland’s minister for finance Michael Doonan said: “It is of utmost importance to me that such a tax is as effective as possible, as fair as possible, and minimises the administrative burden on business.”​ There is also “much analysis”​ that needs to be done before the levy comes in to force, he added.

Food and drink manufacturers remain “adamantly opposed”​ to the fiscal measures. Food and Drink Industry Ireland has claimed they are “unfair, discriminatory and not evidence based”.

Ireland could soon become the most obese country in Europe, according to forecasts by the World Health Organisation.