A study of the soft drink consumption patterns of more than 1000 schoolchildren presented at this year's European Congress on Obesity in Porto, Portugal (17-20 May) shows that overweight and obese children tend to drink more sugar sweetened soft drinks than normal weight children.
The authors, led by Dr Janas Harrington of University College Cork, Ireland, say that taxing such drinks in combination with other public health measures could help in the fight against childhood obesity. The Irish Government plans to introduce a such a tax in 2018.
The obesity epidemic -- around 170 million children worldwide are overweight -- is a public health crisis with the potential to reverse positive trends in life expectancy and undermine the financial viability of health systems.
Although the epidemic has many causes, links between the consumption of SSDs and excessive weight gain in children have been observed. Furthermore, excessive consumption of SSDs is associated with increased prevalence of tooth decay. This new study investigated the association between SSD consumption and overweight and obesity in Irish schoolchildren.
The researchers analysed data from 1075 children aged 8-11 years from the Cork Children's Lifestyle Study (CCLaS), which was conducted in primary schools in Cork City, Ireland in 2012, and was funded by the National Children's Research Centre, Crumlin. Participants completed 3-day food diaries to assess the intake of SSDs. Body mass index (BMI) was used to define obesity. The authors analysed data from children whose reported energy intake was within the normal range (referred to as 'plausible energy reporters; PERs') - a total of 724 children (two-thirds of the sample).
The researchers found that almost 1 in 5 (18%) of children with plausible (normal) energy intake were overweight or obese compared with 1 in 4 of the total sample. The majority (82%) of participants (PERS) consumed SSDs. On average participants drank one standard can (328ml) a day.
SSDs contributed to an average of 6% total calorie intake and almost a quarter (22%) of total sugar intake. Average calories from SSDs increased incrementally between weight categories: SSD contributed 108 kcal for normal weight children and 155kcal for overweight/obese children, equating to 5.8% and 7.6% respectively of total daily calories respectively. Average intake volumes were also 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.
Further analyses showed that high consumers who drank more than half a normal can of SSD per day (>200ml/d) were twice as likely to be overweight or obese than low volume consumers who drank less than half a can per day (<200ml/d), after adjusting for gender, parental education, physical activity and TV viewing. Moreover, the researchers noted a clear trend of decreasing BMI with falling soft drink consumption.
Dr Harrington concludes: "While no single measure will reverse current trends in obesity, given the high level of consumption of sugar-sweetened drinks and the lack of nutritional value of these products, action needs to be taken to reduce consumption, particularly in children. There is a compelling case for the introduction of public policy to reduce sugar-sweetened drink consumption in the population. 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."
The Irish Government plans to introduce a tax on SSDs in 2018. The next steps of this research group will be to monitor consumption of these drinks in the run-up to the introduction of the tax, and to assess the impact of the tax following its introduction.
Dr Harrington adds: "It is unlikely that the introduction of the tax will have a direct short-term impact on obesity levels, it is more likely to have indirect impacts such as reducing the consumption of these beverages; increasing consumption of non-sugar beverages such as water; product re-formulation; and changing public attitudes. This will be a fascinating experiment in public health policy."