In 2015, a series of government documents were published in the UK in relation to obesity, in particular childhood obesity (Children’s Food Trust, 2015; House of Commons Health Committee, 2015; Public Health England, 2015; Royal College of Paediatrics and Child Health, 2015).
The most populist element to emerge, and the one that has generated the greatest interest amongst the lay public, is the sugar tax. Ireland has now followed suit on these proposals, with a sugar tax of 10% proposed to come into effect in 2018.
But are we falling foul of the “single nutrient hypothesis”, i.e. blaming one nutrient for the complex epidemic that is the obesity crisis? And more importantly, could targeting sugar actually be effective? Let’s have a look at the evidence.
Certain key recommendations have been a consistent feature across the various reports published on the issue of sugar consumption and obesity in 2015, namely:
These recommendations are, overall, positive: in particular the proposals to reformulate food and drink products. The problem? They are too broad in scope, lack any clear priorities and ultimately pass the requirement for action and implementation to State legislature. (Rayner, Scarborough & Biggs, 2015).
The difficulty with the emphasis on the State is that we live in a free-market economy, and there is zero political appetite to curb economic growth or interest, for which the food industry is an enormous player. An example of this is the recent “Responsibility Deal” in the UK, which highlighted that at the level of public policy, government attempts to bargain with the food industry are ineffectual (Panjwani & Caraher, 2014).
The “Responsibility Deal” manifested as a voluntary, opt-in scheme which relied on pledges from the food industry. However, the food industry was successful in articulating such “pledges” in their favour, with the result that there has been little meaningful reduction in calorie content of foods (Panjwani & Caraher, 2014).
The evidence suggests that there is little difference in success between voluntary schemes and compulsory schemes, and the only way a voluntary scheme can be effective is if there are penalties for non-participation and sanctions for non-compliance (Brydon 2013). The fact that there were no such mechanisms in the “Responsibility Deal” reflected the fact that compulsory regulation is the only effective means of implementing health policy at the level of industry (Panjwani & Caraher, 2014).
So whether the government like it or not, any changes in the food environment will have to come from regulation, and we need effective public health policy that is firm, evidence-based, and not short-sighted or populist. Industry can’t out-negotiate the State, as happened with the “Responsibility Deal” in the UK.
In light of this, what is the problem with a tax on sugar?
A sugar tax isn’t a new concept, and there is evidence from other similar schemes to draw some conclusions from. The first element is the tax threshold: the various public health documents in the UK came to a consensus that a minimum levy of 10-20% on sugar-sweetened drinks would be required to be of any effect. The UK introduced a 5% tax, which the evidence from other sugar tax programs around the world suggests is too low to have any effect on industry (Lavin & Timson, 2013).
So on this level, credit to the Irish government for at least proposing the minimum tax levy that the evidence suggests may be effective.
The real issue is that a sugar tax reflects reductionist thinking in relation to the obesity epidemic. Extrinsic sugars are a substantial contributor to the chronic excess energy intake that defines the epidemic, but they are not a sole causative agent. The reason sugar-sweetened drinks are a problem is not the sugar per se, it’s the contribution that sugars make to a chronic positive energy balance (particularly in teens, where SSB contribute up to 30% of daily energy intake), which drives weight gain, obesity, and the downstream diet-induced diseases. Chronic excess calorie consumption is the issue. Sugar is one part of that. Hyperpalatable food is a key factor. The food environment is the driver.
The result of this reductionist thinking, is that a sugar tax fails to address the full spectrum of added sugars in the diet, including fruit juices, confectionary and breakfast cereals. To address the full spectrum of these foods requires intervention and regulation at the level of industry, and we’ve seen how any such interventions have failed thus far. The sugar tax becomes an easy option for governments who want to make it look like they are doing something, because influencing food and drink reformulations is likely to be a much longer-term and hard-fought battle with the food industry.
The evidence also suggests that a sugar tax is ineffectual unless regulation of price promotions and marketing are implemented concurrently.
The evidence from the UK shows that retailers are more likely to have price promotions on products containing extrinsic/added sugars, which is a factor contributing to overconsumption (Public Health England 2015). There has also been a rise in promotion of high sugar products in non-food retail outlets [just have a look around the next time you’re at the till in Penny’s].
A positive regulatory recommendation in the UK has been the imposition of a ‘smack’ ban on such foods at checkout points, including in non-food retail outlets (Children’s Food Trust 2015; House of Commons Health Committee 2015). Again, its important to reiterate not to single out sugar, or even fat: it’s minimising features of the food environment that contribute to overconsumption. In this respect, it remains important to emphasise that measures in this area extend beyond high sugar foods and encompass foods high in fat, saturated fat, sugar and salt (Children’s Food Trust 2015; House of Commons Health Committee 2015).
By focusing on foods that are characterised as high-sugar only, not foods high in sugar, salt, and fat in the one product, we’re giving marketing a loophole to work with.
We have known that both adults and children engage with food promotions, influencing their preferences, behaviours and consumption independent of other variables (Public Health England 2015). In the UK, the current 9pm advertising watershed relates to foods high in sugar, fat and salt, creating a loophole whereby a food high in one or a combination of two can still be marketed (Public Health England 2015).
Television watershed advertising bans are also ineffectual because they fail to address the full spectrum of programming, media and devices through which people engage. As it relates to marketing directed at children, which is a major focal point for sugar-sweetened drinks marketing, any ad watershed would have to encompass all programming prior to 9pm (House of Commons Health Committee 2015).
As far as bringing in a tax on sugar is concerned, the government would be advised to heed the evidence from Mexico; the 6% sugar levy in that country lead to an initial decrease in sales, but marketing was ultimately able to offset the effect of the tax on soft drink sales (Public Health England 2015). A sugar tax alone is simply not effective. It needs support from targeted regulation of price promotions, availability and marketing of such products.
A glaring omission is that there is still a lack of food-based recommendations for how to achieve the aim of reducing sugar consumption. Thus, directly reducing the content of sugar in food and drink at the industry level is a valid means achieving a reduction, considering previous public health success with salt reduction (Public Health England 2015). The evidence suggests, however, a greater difficulty in adjusting the palate of the population in relation to sweet tastes than salt; a more immediate solution is to replace extrinsic sugars with artificial sweeteners (House of Commons Health Committee 2015).
Replacing extrinsic sugars in food and drink products with artificial sweeteners is certainly an attractive concept, as it satisfies the desire for sweet while also leading to a dramatic reduction in the calorie consumption at a whole-population level. But this again is where a sugar tax alone fails to see the big picture, because there is no consideration given to behavioural economics.
Concepts such as ‘nudging’ can be employed to influence purchase behaviour (Sunstein, 2009). Influencing the default choice in favour of zero calorie or artificially sweetened beverages could be an important variable. The Local Government Association in the UK identified the simple measure of making salads a default side option instead of chips as one such nudge (Local Government Association 2013). The use of colour-coding soft drinks based on sugar content and healthfulness (red = unhealthy; green = healthy), in conjunction with the display architecture to locate green-labelled items at a more conveniently eye-level, was able to reduce sugary beverage consumption by 25% over 3 months (Thorndike et al., 2012).
There is another example, taken from the environmental realm, which could have enormous application to the food industry. I owe this concept to a colleague, so I don’t lay claim to it. It is the concept of a cap-and-trade approach to unhealthy food and drink products, which would force reformulation of added-sugar products by manufacturers who fail to come within capped limits (Basu & Taylor, 2014). Mimicking carbon emission cap-and-trade, added sugars would be capped at current levels then systematically reduced by a minimum of 1% per year (Basu & Taylor, 2014). It is estimated that such an approach could reduce prevalence of obesity and type-2 diabetes beyond the capacity of current levies on added-sugar products (Basu & Taylor, 2014).
Such an approach would negate valid fears that a sugar tax would disproportionately affect the most disadvantaged in society (House of Commons Health Committee 2015), by focusing the policy on industry.
There is little evidence that shifting the distribution of risk factors for a disease is achievable through a whole-population approach (Adams, 2004). There is compelling rationale for this point in relation to obesity; the evidence suggests that the people most likely to respond to public health messages are those with the healthiest risk-factor profiles and highest socio-economic status (Adams, 2004). For obesity, however, the data is consistent in showing the greatest risk factors to be lower income, lower education level and lower skilled occupancy (National Obesity Observatory, 2012).
Consequently, a population-based approach like a sugar tax has the potential to have minimal influence on those who need it most: lower income families (Adams, 2004). We have previously seen how price promotions can continue to influence purchase behaviour in this regard. The merits of public health interventions in relation to a particular disease depend on the influence of specific risk factors, which differ by disease (Zulman et al., 2008). Obesity is under the influence of multiple different factors, including socio-economic status, ethnicity, urbanisation, food access and nutrition quality (Kumaniyka et al., 2008).
This is why a tax on sugar is a cop out, unless it forms part of a wider strategic approach at regulatory and industry level, addressing the factors driving obesity which are behavioural and/or environmental in nature, and thus beyond the control of the individual (Kumaniyka et al., 2008).
The environmental and behavioural aspects driving obesity warrant a focus “upstream” on policy and environmental change (Kumanyika et al., 2008). An upstream focus, in turn, is more capable of reducing disparity for socially disadvantaged population sub-groups, who currently lack options for healthy eating and have limited resources, particularly financial (Kumanyika et al., 2008).
A global should also retain the ability to direct universal prevention strategies in a targeted manner to more at-risk populations (Kumanyika et al., 2010). Having a targeted element to strategy can therefore focus initiatives in the right direction, namely lower socio-economic areas (Zulman et al., 2008).
A sugar tax alone is not enough. It has the potential to be entirely ineffectual, and primarily impact lower income households. More particularly, it completely and utterly fails to take into account the wider socio-economic, behavioural and environmental factors driving overconsumption and obesity.
Beyond the sugar tax, the debate on ‘Claire Byrne Live’ on Monday night reflected the complete lack of any coherent hierarchy of priorities for the government to implement a strategy on obesity. Implementing interventions like ‘smacks’ (banning high-sugar foods at retail checkout points) and ‘shoves’ (zoning restrictions on fast food outlets around schools), requires legislative initiative.
The complete absence of behavioural economics in the discussion is another notable omission. Further, in my opinion a cap-and-trade model would be more effective than a simple excise duty, as it forces industry into competition for reductions and may have a more pronounced financial and disease risk reduction (Basu & Taylor, 2014).
We can learn from the failed “Responsibility Deal” in the UK, which suggests that mandatory regulation is required for any State regulation of the food industry (Panjwani & Caraher, 2014). Policy at the national and local government level can shift the food environment by legislating for, inter alia, reductions in sugar, fat and salt content of food, fast-food zoning, mandating nutrition standards within schools, ‘nudging’ and altering choice architecture in the retail sector (Kumanyika et al., 2010; Thorndike et al., 2012). Universal policies could then be targeted to more at-risk populations, particularly school-age children.
Adams, J. (2004). When the population approach to prevention puts the health of individuals at risk. International Journal of Epidemiology, 34(1), pp.40-43.
Basu, S. and Lewis, K. (2014). Reducing Added Sugars in the Food Supply Through a Cap-and-Trade Approach. Am J Public Health, 104(12), pp.2432-2438.
Bryden, A., Petticrew, M., Mays, N., Eastmure, E. and Knai, C. (2013). Voluntary agreements between government and businessâ€”A scoping review of the literature with specific reference to the Public Health Responsibility Deal. Health Policy, 110(2-3), pp.186-197.
Children’s Food Trust, (2015). Child Obesity: their lives in our hands.
House of Commons Health Committee, (2015). Childhood obesity – brave and bold action. London: The Stationary Office Limited.
Institute of Medicine (U.S.)., Kumanyika, S., Parker, L., Sim, L., Leslie J. Sim., Lynn Parker., and Shiriki K. Kumanyika., (2010). Bridging the Evidence Gap in Obesity Prevention: A Framework to Inform Decision Making. National Academies Press.
Kumanyika, S., Obarzanek, E., Stettler, N., Bell, R., Field, A., Fortmann, S., Franklin, B., Gillman, M., Lewis, C., Poston, W., Stevens, J. and Hong, Y. (2008). Population-Based Prevention of Obesity: The Need for Comprehensive Promotion of Healthful Eating, Physical Activity, and Energy Balance: A Scientific Statement From American Heart Association Council on Epidemiology and Prevention, Interdisciplinary Committee for Prevention (Formerly the Expert Panel on Population and Prevention Science). Circulation, 118(4), pp.428-464.
Lavin, R. and Timpson, H. (2013). Exploring the Acceptability of a Tax on Sugar-Sweetened Beverages. Liverpool: John Moores University.
Local Government Association, (2013). Changing behaviours in public health: to nudge or to shove?. London: Local Government Association.
National Obesity Observatory, (2012). Adult Obesity and Socioeconomic Status Factsheet. London: National Health Service.
Panjwani, C. and Caraher, M. (2014). The Public Health Responsibility Deal: brokering a deal for public health, but on whose terms?. Health Policy, 144(2), pp.163-173.
Public Health England, (2015). Sugar Reduction: the evidence for action.
Public Health England, (2015). Obesity and the environment briefing: regulating the growth of fast food outlets. London: Public Health England.
Rayner, M., Scarborough, P. and Briggs, A. (2015). Public Health England’s report on sugar reduction. BMJ, 351(nov19 11), pp.h6095-h6095.
Rose, D. (2007). Food Stamps, the Thrifty Food Plan, and Meal Preparation: The Importance of the Time Dimension for US Nutrition Policy. Journal of Nutrition Education and Behavior, 39(4), pp.226-232.
Royal College of Paediatrics and Child Health, (2015). Tackling England’s childhood obesity crisis.
Thorndike, A., Sonnenberg, L., Riis, J., Barraclough, S. and Levy, D. (2012). A 2-Phase Labeling and Choice Architecture Intervention to Improve Healthy Food and Beverage Choices. Am J Public Health, 102(3), pp.527-533.
ZULMAN, D., VIJAN, S., OMENN, G. and HAYWARD, R. (2008). The Relative Merits of Population-Based and Targeted Prevention Strategies. Milbank Quarterly, 86(4), pp.557-580.