A groundbreaking study from the University of Auckland has uncovered a dramatic shift in New Zealand's food landscape, revealing that imports of ultra-processed foods (UPFs)—defined by the NOVA classification system as industrial formulations typically high in added sugars, unhealthy fats, salt, and artificial additives—have surged from just 9% of total food and beverage imports in 1990 to 22% in 2023. This equates to a per capita increase from 15.7 kilograms to 103.8 kilograms annually, highlighting how trade liberalization has flooded the market with convenient but nutrient-poor products like sugary drinks, savoury snacks, and ready meals.
Led by Kelly Garton from the School of Population Health, alongside colleagues Gabriela Lopes da Cruz and Boyd Swinburn, the research draws on United Nations Comtrade data spanning 34 years. It categorizes 898 Harmonized System codes into NOVA groups: Group 1 (unprocessed/minimally processed foods like fresh fruits and vegetables), Group 2 (culinary ingredients like oils and sugar), Group 3 (processed foods like canned vegetables), and Group 4 (UPFs). The findings underscore a troubling trend where UPF inputs—such as industrial sugars, modified oils, and emulsifiers—have overtaken finished UPF products in import volumes since 2011, fueling local manufacturing of hyper-palatable items.
Understanding Ultra-Processed Foods: The NOVA Framework Explained
Ultra-processed foods represent the most industrialized end of the food spectrum under the NOVA system, developed by researchers at the University of São Paulo. Unlike minimally processed foods (e.g., frozen berries or pasteurised milk), which retain their natural qualities, UPFs undergo multiple processes involving substances not used in home cooking, such as high-fructose corn syrup, hydrogenated oils, and flavour enhancers. Examples commonly imported to New Zealand include carbonated soft drinks, potato chips, instant noodles, and pre-packaged pizzas. These products are designed for long shelf life, convenience, and sensory appeal, often displacing healthier options in daily diets.
In New Zealand supermarkets, UPFs comprise about 70-84% of packaged products, according to earlier audits, with the worst nutrient profiles—high in energy density but low in protein, fiber, and micronutrients. This dominance is not accidental; it's a byproduct of global food systems prioritizing profit over nutrition.
Methodology: A Retrospective Analysis of Trade Data
The study meticulously analyzed annual import volumes from 1990 to 2023 using UN Comtrade's Harmonized System codes, calculating total and per capita figures adjusted for population growth. Tariff data from the World Trade Organization showed progressive reductions to near-zero levels, particularly post-1995 WTO accession and around 2007-08 free trade agreements. Subgroup analysis distinguished UPF finished products from inputs, revealing how imported additives enable domestic ultra-processing. This step-by-step approach—data extraction, NOVA classification, volume computation, and trend modeling—provides robust evidence unmarred by self-reported consumption biases, as New Zealand lacks a recent national nutrition survey since 2008.
Key Statistics: Quantifying the Import Explosion
- UPF share in total imports: 8.7% (1990) to 21.8% (2023).
- Per capita UPF volume: 15.7 kg to 103.8 kg—a 561% increase.
- UPF inputs (e.g., 21 kg industrial sweeteners per person in 2023, plus 47 kg regular sugar): now the largest subgroup.
- Notable growth in sweetened drinks, processed snacks, and wheat flours used in baking ultra-processed goods.
Minimally processed imports grew too, but lagged behind, with tariffs historically favoring processed categories minimally.
| Year | UPF Per Capita (kg) | % of Total Imports |
|---|---|---|
| 1990 | 15.7 | 8.7 |
| 2000 | ~45 (est.) | ~14 |
| 2023 | 103.8 | 21.8 |
From Imports to Diets: UPF Dominance in Supermarkets and Households
New Zealand relies heavily on imports for 80-90% of its food energy, exacerbating UPF penetration. Supermarket audits show UPFs as 83-84% of packaged items, comprising half of total energy intake—similar to Australia and Canada. One in three households faces food insecurity per the 2025 Hunger Monitor, pushing reliance on cheap UPFs amid rising costs. Children consume nearly half their energy from UPFs by age one, rising further, correlating with early obesity risks.
This supermarket study confirms UPFs' poor nutrient profiles drive unhealthy choices.
Health Impacts: Obesity, Diabetes, and a Mounting Crisis
UPF-heavy diets contribute to New Zealand's obesity epidemic: 34.2% of adults obese in 2024/25 (up from 31.3% pre-COVID), with only 31% at healthy weight. Child obesity stands at 11.7%. Diabetes affects over 250,000, mostly type 2, projected to 430,000 by 2040. Globally, UPFs link to 32 health outcomes, including 18% of premature deaths from diet/excess weight. In NZ, Pacific and Māori populations bear disproportionate burdens, compounded by inequities.
Mechanisms include hyper-palatability disrupting satiety, additives promoting overeating, and low fiber/satiety leading to energy imbalance.
Trade Liberalization: The Economic Driver Behind the Shift
Post-1980s neoliberal reforms and WTO entry slashed tariffs, enabling UPF influx. Free trade deals further liberalized access, with minimal protections for healthy imports. This mirrors global patterns where transnational corporations expand UPF markets, prioritizing volume over nutrition.
Stakeholder Perspectives: Voices from Academia and Beyond
Lead researcher Kelly Garton, on a Heart Foundation Fellowship, emphasizes monitoring trade's nutrition impacts. Co-author Boyd Swinburn, a global food policy expert, advocates comprehensive reforms. Nutritionists note time-poor families favor UPF convenience, while industry defends reformulation. Māori health advocates highlight cultural food sovereignty erosion.
Policy Pathways: Proven Solutions and NZ Proposals
New Zealand lags best practice. Recommendations include:
- Mandatory front-of-pack labelling (like Chile's octagons, reducing UPF purchases 25%).
- Sugary drink levy (Mexico saw 10% drop).
- Marketing bans for kids' UPFs.
- Reformulation targets for salt/sugar.
- Subsidies for whole foods.
Voluntary Health Star Ratings may become mandatory; researchers urge bolder action.Garton's Conversation piece details these.
International Lessons: Successes from Latin America
Brazil, Chile, Mexico use warning labels on high-sugar/salt/fat UPFs, reformulated products, and cut child-targeted ads—reducing consumption 15-30%. NZ could adapt these, balancing trade obligations.
Photo by Kishan Modi on Unsplash
Future Outlook: Research Needs and Public Health Imperative
Without intervention, UPF dominance threatens NZ's health targets. University research like Auckland's is vital; more funding for nutrition epidemiology could guide policy. Actionable insights: prioritize whole foods, support local producers, advocate for regs. The study signals urgency for a healthier food system.
For deeper dive, read the full open-access paper.
