05 Apr 2023 Blog: Marking 5 years of the Soft Drinks Industry Levy – how can sugar taxes support children and young people’s health?
The 5th April marks an important anniversary for public health policy in the UK. Five years ago today, the UK Government officially introduced the Soft Drinks Industry Levy (SDIL). Designed as a tax to encourage soft drink manufacturers to reduce the sugar content of their drinks, the SDIL has removed over 45,000 tonnes of sugar from soft drinks from supermarket shelves.
According to the World Health Organisation (WHO), over 85 countries and cities currently operate a form of a tax on sugar-sweetened beverages (SSBs) and promote such taxes as an evidence-based policy option for the prevention of non-communicable diseases.
This is in light of the evidence that shows frequent consumption of SSBs is associated with several implications on children and young people’s (CYP) health – including weight gain, tooth decay and type 2 diabetes.
The SDIL was announced in the UK in Part 1 of the Childhood Obesity Plan in 2018, in a bid to promote healthier weight in children and young people.
However, leading researchers in the field have argued that the evidence on SSB taxes largely relate to impact on sales and purchases of SSBs, and overall reductions in sugar content of SSBs. Yet the evidence supporting claims on beneficial impacts to CYPs health is not as strong. There is also limited evidence demonstrating the role of SSB taxes on oral health.
Food Active recently undertook a Rapid Evidence Assessment* (REA) on the impact of SSB taxes on CYP’s health, to better understand what the current evidence base can tell us and inform a series of recommendations for policymakers and future research. The REA includes 20 research papers* conducted across the globe, including two studies conducted in the UK to model the potential impacts of the SDIL, and another tracking associations between children’s weight through the National Child Measurement Programme and the implementation of the SDIL. This blog is a summary of this REA, and the key findings are represented in the infographic below.
Can SSB taxes improve children and young people’s diets?
- 11 studies identified in this REA provided data on associations between SSBTs and diet quality of CYP, overall providing mixed evidence.
- Proxy measures for diet quality included reductions in daily SSB consumption and total energy intake. Measured outcomes varied greatly amongst the studies identified.
- This REA presents mixed evidence on whether SSBTs can reduce CYP’s SSB consumption. However, consistent evidence suggests they may play a role in supporting high consumers of SSBs and particular ethnic groups to reduce their overall SSB consumption.
- This REA also presents consistent evidence that SSBTs may play a role in encouraging small reductions in overall calorie intake in CYP, with adolescents potentially experiencing the greatest reductions
Can SSB taxes promote healthier weight in children and young people?
- 10 studies identified in this REA gathered data on SSBTs and CYP’s Body Mass Index (BMI) or weight status.
- The outcomes measured varied from reduction in BMI-score, weight (kg), prevalence of obesity (%) and the number of prevented cases of obesity.
- This REA presents mixed evidence on whether SSBT can reduce CYP’s BMI or weight. Eight studies reported an association between the implementation of a SSBT and CYP’s BMI or weight. The remaining two studies failed to find a significant effect on CYP’s BMI or weight.
- There was consistent evidence that some demographics may experience greater reductions compared to all CYP. This included adolescents, girls and low-income adolescents.
- There was consistent evidence that increasing the SSBT threshold may be associated with greater reductions to BMI-score and weight in CYP.
- Two studies containing data on CYP weight were conducted in the UK. These included:
- Rogers et al., (2023) which reported a 8% reduction in the prevalence of obesity in girls aged 10/11 years old since the implementation of a SSBT in the UK; which rose to 11% within the most deprived quintiles. No such reductions were reported for boys.
- Briggs et al. (2017) modelled the potential impacts of the SDIL prior to implementation.
Can SSB taxes promote good oral health outcomes in children and young people?
- Four studies examining the impact of SSBTs on CYP’s oral health were identified in this REA.
- Outcomes measured varied across the studies, including the number of cases of decayed, missing or milled teeth (DFMT) prevented, reduction of DFMT per child, caries-free tooth years gained, and number of caries lesions prevented.
- This REA presents consistent evidence that SSBTs may be associated with positive oral health outcomes for CYP.
- This REA presents consistent evidence that boys and adolescent males would benefit the most from SSBTs in terms of oral health improvements.
Conclusions and recommendations
It is clear to see that SSBT have the potential to make a small and positive impact on CYP health, however there are some important aspects that policymakers need to consider.
This REA identified that the greater the SSBT threshold, the greater the health benefits to CYP. This is echoed by the WHO, who recommend a 20% tax is the minimum threshold to support improvements to health (World Health Organisation, 2022). Studies identified in this REA which used lower thresholds of 10% had markedly lower health benefits for CYP.
Substitution effects of SSBT were also not measured in most of the studies identified in this REA. Where they were measured, effects included an increase in consumption of non-taxed drinks such as milk-based drinks and fruit juices. In the UK, such drinks are exempt from the SDIL and are now some of the most sugar-dense drinks available on the market (for example a 400ml of Friji Fudge Brownie Milkshake contains 43.6g sugar – accounting for 145% of an adults recommended sugar intake and 181% of a child aged 7-10’s recommended intake). Substitution effects are important to consider in terms of the wider impacts on the diet of SSBT, and whether policymakers need to extend the tax to these drinks to ensure the benefits to CYP’s health are harnessed.
Furthermore, this REA suggests there may be a relationship between SSBT and CYP obesity prevalence in those living in deprived and low-income households. SSBTs may therefore support wider efforts to reduce the obesity gap between the most and least deprived children and address health inequalities, which is commonly reported in economically developed countries. In the UK, the latest NCMP figures demonstrate that children living in the most deprived households are more than twice as likely to experience overweight or obesity when compared to their more affluent peers – and the gap continues to grow.
Finally, even where improvements to CYP diet, weight and oral health have been reported, these are relatively small changes. It is important to recognise that the impact of SSBTs on CYP’s health will be limited in isolation and in the absence of additional policy measures. SSBTs should therefore be regarded as one component of a wider strategy to tackle the complex issues of poor diet, obesity, and poor oral health, as opposed to a ‘silver bullet’. Policymakers should explore other options in tandem to maximise the potential of SSBTs and address other drivers of these issues, such as food and drink marketing and advertising. Here in the UK, important legislation to limit the advertising and marketing of less healthy food and drink, including SSBs, has just been delayed until October 2025. The initial implementation date was the end of 2022. These delays come at a time where 10.1% of 5-year-olds are living with obesity, and 29.3% have enamel and/or dentinal decay.
The SDIL is considered as a key milestone for public health, however the benefits will only be maximised when it has been bolstered by other important measures that seek to address other drivers of obesity and poor oral health in CYP.
* This REA was conducted in March 2023 following the Collins et al. (2015) framework. A maximum of 20 papers were gathered through two databases (SCOPUS and Web of Science), using search terms which have been refined and tested. The papers included in this assessment were:
- Torres-Álvarez, R., Barrán-Zubaran, R., Canto-Osorio, F., Sánchez-Romero, L.M., Camacho-García-Formentí, D., Popkin, B.M., Rivera, J.A., Meza, R. and Barrientos-Gutiérrez, T. (2020) ‘Body weight impact of the sugar-sweetened beverages tax in Mexican children: A modeling study’, Pediatric Obesity, 15(8), pp. e12636. doi: 10.1111/ijpo.12636.
- Cawley, J., Daly, M. and Thornton, R. (2022) ‘The effect of beverage taxes on youth consumption and body mass index: Evidence from Mauritius’, Health Economics, 31(6), pp. 1033-1045. doi: 10.1002/hec.4497.
- Cawley, J., Frisvold, D., Hill, A. and Jones, D. (2019) ‘The impact of the Philadelphia beverage tax on purchases and consumption by adults and children’, Journal of health economics, 67, pp. 102225. doi: 10.1016/j.jhealeco.2019.102225.
- Rogers, N.T., Cummins, S., Forde, H., Jones, C.P., Mytton, O., Rutter, H., Sharp, S.J., Theis, D., White, M. and Adams, J. (2023) ‘Associations between trajectories of obesity prevalence in English primary school children and the UK soft drinks industry levy: An interrupted time series analysis of surveillance data’, PLoS medicine, 20(1), pp. e1004160. doi: 10.1371/journal.pmed.1004160.
- Cawley, J., Frisvold, D., Hill, A. and Jones, D. (2020) ‘Oakland’s sugar-sweetened beverage tax: Impacts on prices, purchases and consumption by adults and children’, Economics & Human Biology, 37, pp. 100865. doi: 10.1016/j.ehb.2020.100865.
- Goiana-da-Silva, F., Severo, M., Cruz E Silva, D., Gregório, M.J., Allen, L.N., Muc, M., Morais Nunes, A., Torres, D., Miraldo, M., Ashrafian, H., Rito, A., Wickramasinghe, K., Breda, J., Darzi, A., Araújo, F. and Lopes, C. (2020) ‘Projected impact of the Portuguese sugar-sweetened beverage tax on obesity incidence across different age groups: A modelling study’, PLoS medicine, 17(3), pp. e1003036. doi: 10.1371/journal.pmed.1003036.
- Gracner, T., Marquez-Padilla, F. and Hernandez-Cortes, D. (2021) ‘Changes in Weight-Related Outcomes Among Adolescents Following Consumer Price Increases of Taxed Sugar-Sweetened Beverages’, JAMA pediatrics, 176(2), pp. 150-158. doi: 10.1001/jamapediatrics.2021.5044.
- Flynn, J. (2023) ‘Do sugar-sweetened beverage taxes improve public health for high school aged adolescents?’, Health Economics, 32(1), pp. 47-64. doi: 10.1002/hec.4609.
- Chatelan, A., Rouche, M., Dzielska, A., Fismen, A., Kelly, C., Pedroni, C., Desbouys, L. and Castetbon, K. (2022) ‘Sixteen-year trends in adolescent consumption of sugar-sweetened soda in six European countries with a soda tax and comparison countries: a repeated cross-sectional survey analysis’, Public health nutrition, , pp. 1-12. doi: 10.1017/S1368980022002361.
- Jevdjevic, M., Trescher, A.-., Rovers, M. and Listl, S. (2019) ‘The caries-related cost and effects of a tax on sugar-sweetened beverages’, Public health, 169, pp. 125-132. doi: 10.1016/j.puhe.2019.02.010.
- Schwendicke, F. and Stolpe, M. (2017) ‘Taxing sugar-sweetened beverages: impact on overweight and obesity in Germany’, BMC public health, 17(1), pp. 88. doi: 10.1186/s12889-016-3938-4.
- N. Ford, J. M. Poti, S. W. Ng, B. M. Popkin (2017) ‘SSBTes and diet quality in US preschoolers: estimated changes in the 2010 Healthy Eating Index SSBTes and diet quality in pre-k’, Pediatric obesity, 12(2), pp. 146-154.
- Briggs, A.D.M., Mytton, O.T., Kehlbacher, A., Tiffin, R., Elhussein, A., Rayner, M., Jebb, S.A., Blakely, T. and Scarborough, P. (2017) ‘Health impact assessment of the UK soft drinks industry levy: a comparative risk assessment modelling study’, The Lancet Public Health, 2(1), pp. e15-e22. doi: 10.1016/S2468-2667(16)30037-8.
- Phonsuk, P., Vongmongkol, V., Ponguttha, S., Suphanchaimat, R., Rojroongwasinkul, N. and Swinburn, B.A. (2021) ‘Impacts of a sugar sweetened beverage tax on body mass index and obesity in Thailand: A modelling study’, PloS one, 16(4), pp. e0250841. doi: 10.1371/journal.pone.0250841.
- Sowa, P.M. and Birch, S. (2022) ‘The effects of a sugar-sweetened beverage tax: moving beyond dental health outcomes and service utilisation’, Health Economics, Policy and Law, , pp. 1-15. doi: 10.1017/S1744133122000147.
- Lal, A., Mantilla-Herrera, A.M., Veerman, L., Backholer, K., Sacks, G., Moodie, M., Siahpush, M., Carter, R. and Peeters, A. (2020) Modelled health benefits of a sugar-sweetened beverage tax across different socioeconomic groups in Australia: A cost-effectiveness and equity analysis’, PLoS medicine, 17(7), pp. e1003310. doi: 10.1371/journal.pmed.1003310.
- Wrottesley, S.V., Stacey, N., Mukoma, G., Hofman, K.J. and Norris, S.A. (2021) ‘Assessing sugar-sweetened beverage intakes, added sugar intakes and BMI before and after the implementation of a sugar-sweetened beverage tax in South Africa’, Public health nutrition, 24(10), pp. 2900-2910. doi: 10.1017/S1368980020005078.
- Alhareky, M., Bedi, S., AlMulhim, A., El Tantawi, M., Farooqi, F.A. and AlHumaid, J. (2021) ‘Impact of Sugar Tax on Sugar-sweetened Beverage Consumption among Saudi Schoolchildren’, Oral health & preventive dentistry, 19(1), pp. 189-194.
- Restrepo, B.J. (2020) ‘The effects of soda taxes on adolescent sugar intake and blood sugar’, Health Economics, 29(11), pp. 1422-1434.
 World Health Organisation (2022) WHO manual on sugar-sweetened beverage taxation policies to promote healthy diets. Geneva: World Health Organisation. Available at: https://www.who.int/publications/i/item/9789240056299 (Accessed: 29th March 2023).
 Bucher Della Torre, S., Keller, A., Depeyre, L.J., and Kruseman, M. (2016) ‘Sugar-Sweetened Beverages and Obesity Risk in Children and Adolescents: A Systematic Analysis on How Methodological Quality May Influence Conclusions’, Journal of the Academy of Nutrition and Dietetics, 116(4), pp. 638-659. doi: 10.1016/j.jand.2015.05.020.
 Valenzuela, M.J., Waterhouse, B., Aggarwal, V.R., Bloor, K. and Doran, T. (2021) ‘Effect of sugar-sweetened beverages on oral health: a systematic review and meta-analysis’, European journal of public health, 31(1), pp. 122-129. doi: 10.1093/eurpub/ckaa147.
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