Summary

Aotearoa New Zealand’s (NZ) approach to the obesogenic food environment is not working. Action on prevention is vital in the context of increasing pressures on the health system, and the lack of improvement in obesity trends impacting on chronic disease burden into the future. Effective public health policies are urgently needed to reverse the deteriorating obesogenic food environment and improve nutrition in NZ. 

A UK-style sugary drinks industry levy is a key facet of health policy for improving nutrition and preventing dental decay. Recently published evidence from Tonga shows how excise taxes directed towards unhealthy foods were effective at increasing prices and decreasing import volumes of these foods. 

NZ’s unhealthy food environment problem

As New Zealanders, we live in an obesogenic environment – ie, a setting that promotes weight gain and makes it hard to maintain a healthy weight. NZ has the third highest rate of obesity in the OECD.1 A close look at the NZ Health Survey makes it clear that obesity trends are not improving (Figure 1),2 and if anything, they may still be increasing. There has been no improvement for any ethnicity group except for a possible plateau for Māori (Figure 2). Disparities continue to be wide, with the concentration of obesogenic environments characterised by fast-food outlets, convenience stores, and unhealthy food advertising in high-deprivation areas.3 Almost every age group has experienced increasing obesity, from school-aged children to older adults (Figure 3), although obesity rates appear to have stabilised in pre-schoolers, 35 to 44-year-olds and 65 to 74-year-olds. 

Worsening obesity trends implicate widespread deterioration in food environments where people spend most of their time, including school, work and communities. Our society has normalised the sale, marketing and availability of sugary drinks and energy-dense ultra-processed foods. Sugary drinks are the leading source of sugar in our children’s diet (26% of total sugar intake in children4 and 17% in adults5). These products are directly related to rates of dental decay, diabetes, heart disease, strokes, cancer and mental ill health.6,7 We allow businesses and organisations to profit off products that contribute to these diseases, without contributing to the resulting healthcare costs. Political lobbying by the ultra-processed food industry impedes implementation of public health policies.8

 

Figure 1: New Zealand’s obesity trends are not improving, and they may still be getting worse

Figure 2: Obesity rates have not improved in any ethnicity group, and disparities by ethnic group are stark.

Figure 3: Obesity rates have increased across almost every age group

Note: Figures 1 and 2 report total obesity prevalence, with no adjustment for age. Figure 3 obesity prevalence estimates were derived using available multi-year averaged survey results  (see Appendix).

Obesity (and associated dietary) trends have huge implications for the current burden of disease and health system pressures, which are forecast to increase into the future.9  The NZ health system is already under growing pressure from population ageing and population growth and stands to significantly benefit from reductions in preventable disease. Over a third of health loss in NZ could be prevented, 10 with high BMI as the top risk factor, overtaking tobacco use.9,10 Obesity related disease results in health costs of upwards of NZ$2 billion annually.11 Reducing obesity in NZ to what is seen in the best performing OECD countries is estimated to avoid 14,500 NCD cases each year and 785 premature deaths, result in 3.1% lower health expenditure, increase workforce output by 33,900 FTE and lift GDP by 1.1%.9 

Our health system, economic productivity, families and communities urgently need effective policy action on disease prevention. Government action on unhealthy food is urgently needed,12 such as the sugary drinks industry levy called for by Health Coalition Aotearoa alongside the call for regulating food marketing to children and providing permanent funding for the healthy school lunches programme. Trends in sugary drinks and unhealthy food consumption have not been given due attention in NZ, with the National Nutrition Survey 17 years out-of-date.4,5 Its reintroduction is urgently needed to monitor progress (or lack of it). 

International leadership

Countries around the world have responded to the obesogenic food environment, with over 100 jurisdictions introducing levies on sugary drinks. Many evaluations of these policies are available, with meta-analyses reporting that for every 10% increase in the price of sugary drinks, there was an average decrease of 16% in sales (L),13 and a 10% decrease in purchasing and dietary intake (L).14 In 2026, two-thirds of New Zealanders surveyed support a sugary drinks levy (and there was three-quarters support it if it was used to make healthy food more available/affordable).15 Increasingly, countries are introducing further prevention policies such as taxes on unhealthy foods,16-18 marketing bans for children,19,20 compulsory food warning labels.21

Tonga unhealthy food tax and tariff waiver evaluation

The highest childhood obesity rates in the world are found in the Pacific,22 and NZ the largest exporter or sugary drinks to this region.23 Three-quarters of Pacific countries have responded to the obesogenic environment and introduced sugary drinks levies.24 Tonga has introduced excise taxes on sugary drinks, mutton flaps, turkey tails, sausages, corned beef, sweets/chocolate, biscuits, and ice cream between 2013 and 2018 (all 95%+ imported); while also removing import tariffs on fruit, vegetables and fish.Funded by a Marsden grant, we closely studied the effects of Tonga’s food tax policies on prices, imports and household purchases, while adjusting for pre-existing trends, international prices and economic changes. Not surprisingly, Tonga’s policies were associated with statistically significant increases in retail prices of unhealthy foods and reductions in import volumes of the taxed unhealthy foods–soon to be published in Public Health Nutrition(preprint).25 The taxed foods that responded most to tax increases were discretionary foods such as sugary drinks, ice cream and sausages. We found no evidence of switching to unhealthy imported foods,25  with the exception being a possible shift to untaxed meat imports in 2016 with the introduction of tax on turkey tails, mutton flaps, and chicken legs. For the sugary drinks tax,26 we found no evidence of substitution from imported sugary drinks to other imported beverages; however, there was increased local manufacturing of bottled water and soft drinks. The latter, however, was dwarfed by import declines in sweetened drinks.26Removing import tariffs on selected healthier foods did not have the desired effects, with limited pass-through of the cost of the tax to the consumer  and an unexpected falling trend in imports of these foods – as recently published in BMJ Public Health.27Our research highlights the strength of tax on unhealthy food for improving the food environment. Findings contribute to the wider international literature, which demonstrates the nutrition benefits of taxes on sugar drinks and unhealthy foods. What could NZ do to prevent obesity and chronic disease? 

A sugary drinks levy such as the UK-style sugary drinks industry levy is one of the most effective evidence-based13,14 measures we could have for rebalancing the food environment and improving health equity in NZ.28 

The UK levy has a tiered structure, so that drinks with no/low sugar (<4.5g/100ml) are exempt. Drinks with moderate sugar (4.5-8g/100ml) are moderately taxed eg, NZ$1 a litre, and drinks with the highest sugar (8g+/100ml) are taxed more eg, NZ$1.50 a litre. The levy applies to importers and manufacturers of carbonated soft drinks, energy drinks, cordials, fruit drinks, sweetened milk drinks, sports drinks and zero-alcohol drinks. 

The tiered approach incentivises industry to take the sugar out of sugary drinks eg, reducing sugar by 30% in the UK,29 (NZ drinks remain far too sugary30), which leads to a significant improvement in the availability of no/low sugar healthy alternatives. 

Industry that continues to profit off selling sugary beverages remains subject to paying the levy, and thus begins to contribute to the healthcare costs associated with their products. 

For greater acceptability and equity, revenue can be used to support low-income households, eg, by extending free dental care and making healthy foods more available via food relief programmes and an improved school lunch programme. 

Action taken now on sugary drinks will reduce dental decay and childhood obesity, and drive long-term reductions in rates of chronic disease and health expenditure, particularly in groups most exposed to the obesogenic environment. Findings from Tonga, the UK and elsewhere show what is possible with strong policy leadership. 

What this Briefing addsNZ’s approach to the obesogenic food environment is not working. NZ has the third-highest obesity rates in the OECD, and there is no evidence that obesity has stopped increasing. This is driving increasing rates of preventable disease, health expenditure and health inequities. Newly published evidence highlights positive impacts of Tonga’s excise taxes on sugary drinks and unhealthy food. There were significant increases in prices and reductions in import volumes of unhealthy foods, with no evidence of switching to unhealthy untaxed foods. Implications for policy and practicePolicy action is urgently needed to help manage the increasing demands on the NZ health system driven by a food environment which is not supporting healthy choices.A UK-style sugary drinks industry levy is one of the most effective evidence-based measures we could use for rebalancing the obesogenic food environment, reducing obesity rates and improving health equity in Aotearoa.A National Nutrition Survey is vital to monitoring progress and needs to be funded. 

 

Authors details 

Dr Andrea Teng, Department of Public Health, University of Otago, Wellington | Ōtākou Whakaihu Waka, Pōneke

Associate Professor Cristina Cleghorn, Department of Public Health, Ōtākou Whakaihu Waka, Pōneke | University of Otago, Wellington

Alice Kim, Biostatistics Group – Ratonga Tauanga Koiora, University of Otago, Wellington | Ōtākou Whakaihu Waka, Pōneke

Dr Viliami Puloka, Health Promotion and Policy Research Unit, Department of Public Health, Ōtākou Whakaihu Waka, Pōneke | University of Otago, Wellington

Professor Nick Wilson, Co-Director of the Public Health Communication Centre, and Department of Public Health, Ōtākou Whakaihu Waka, Pōneke | University of Otago, Wellington

 

Appendix

The most recent annual health survey results were averages across four- and five-year groupings. The NZ Health Survey did not collect obesity data in the twelve months from July 2021 to June 2022. The midpoint used for the 75+ age-group was 82 years old, and for the 71+ age group in 2009 it was 78 years old. The 2002/03 NZ Health Survey did not report obesity for <15 years olds. Age groups were: 2-4y, 5-9y, 10-14y, 15-24y, 25-34y, 35-44y, 45-54y, 55-64y, 65-74y, 75+y (except for 2009).