1.1. The Problem of Food Waste and Food Sustainability: Internationally and in Aotearoa New Zealand
Internationally, food waste has received significant attention in recent academic discourse due to the staggering figures of an estimated 1.3 billion tonnes of food being wasted globally each year [1
]. The UN Environment Programme’s (UNEP) Food Waste Index suggests that around 17% of global food production may go to waste, with 61% of this waste from domestic sources [2
]. The environmental degradation that occurs due to food waste–the excess methane and landfill leachate production, or additional dump space required when organic material is landfilled, not to mention the fossil fuels and greenhouse gases generated in the food’s production–is unjustified when food waste is avoidable. According to the United Nations Food and Agriculture Organisation, the 931 million tonnes of food (1/3 of the world’s food) that is unconsumed each year is estimated to generate between 8–10% of global carbon emissions [1
The UN organisation Food Use for Social Innovation by Optimising Waste Prevention Strategies (FUSIONS) offers an inclusive definition of food waste that has been adopted across the European Union [3
]. FUSIONS’ definition of food waste has been simplified by Goodman et al. [4
] as: “Any food, and inedible parts of food, removed from the food supply chain to be recovered or disposed of (excludes food that is donated to humans or animals)” (p. 2). The inedible parts of food are included in the definition of food waste to encourage a food system that uses all parts of e.g., an animal, or vegetable. However, food donated to humans or animals is omitted because it is considered food diversion, or food waste prevention [3
]. For this study only food wastage that occurred in the household was examined, as part of a suite of domestic food planning, preparation, and waste behaviours.
Most food waste studies have focused on quantifying the total food lost along the supply chain [5
]. In the European Union alone 180 kg of food per person is wasted every year [7
]. A US study on 39,758 individuals indicated that in 2008 wasted food averaged 124 kg, or economic losses of US $
390 per capita per year [8
]. In comparison, the Australia 2019 National Food Waste Baseline Project quantified food waste at 298 kg/year/person [9
]. While the large variability in food waste volume per capita, per year could be down to differences in food waste behaviours and infrastructures between countries, the lack of standard international measures in place to compare waste volumes make absolute comparisons impractical. Other studies have honed in on what is wasted in the retail sector (see studies in the UK [10
], Sweden [12
], and New Zealand [4
]). However, there is evidence that it is at the level of the household that the most food waste is generated [13
Australia has adopted a national waste reduction target aligned to SDG 12.3 that incorporates household food waste, and there have been calls for NZ to do the same [14
]) (p. 8). In Aotearoa New Zealand (NZ) a 2013 WasteMINZ campaign was launched, with initial studies auditing 1402 household rubbish bins across 12 council jurisdictions, and administering household food waste diaries to quantify and qualify food waste nationally. This was followed by a food waste attitudes and values survey in 2014, of 1365 respondents [15
]. Of the data captured there was little change between surveys undertaken in 2014 and a follow up study undertaken in 2018 [16
]. Between surveys, self-declarations of the percentage of food wasted remained at ~5% of a household’s weekly food expenditure, equating to ~NZ $
390 per household per year, or ~NZ $
144 per capita per year. Further, the demographic profile of ‘high food wasters’ also remained consistent between surveys, correlating with: “younger people i.e., those aged 16 to 24 years in the household responsible or jointly responsible for food shopping and preparation; large households i.e., those with four or more people living in them, households with children aged 15 years and under; and households with a high annual income (NZ $
100,000 per annum or more)” [15
] (p. 3]. In 2018 in New Zealand, the average household was estimated to be responsible for wasting ~164 kg/year of food of which 86 kg is ‘avoidable’ (or 61 kg of food waste and 32 kg of ‘avoidable’ food waste, per person, per year) [16
] (p. 2).
While the overall volumes did not appear to change much between surveys [15
] (p. 3), the reasons given for household food wastage did change between 2014 and 2018. Significant differences were around participants’ claims that the main reasons that food was wasted in their household were: because leftovers were uneaten (31% in 2014 to 23% in 2018), food went ‘off’ (25% in 2014 to 21% in 2018), too much food was cooked (11% to 15%), and too much food was purchased (9% to 15%) [17
] (p. 50). Food waste in the 2018 survey was particularly high amongst 16–24-year-olds, (44% of whom agreed with this statement compared with 27% of the total sample of 1300 individuals) (p. 21). Of this demographic group busy lifestyles were stated as making it hard to avoid wasting food (50% compared with 34% of the total sample) (p. 24). These assessments were all conducted in pre-Covid times.
Despite these available figures on household food waste, it must be noted that inventories of household waste even in ‘normal’ (i.e., pre-COVID-19) times are challenging to undertake, with the actual total amount of food lost or wasted in New Zealand unknown and its disaggregation (for example to the household level) imprecise. In NZ, food waste data has been noted as “a gap in the country’s environmental reporting” [14
] (p. 5). The household is chronologically last in the food supply chain and known to generate significant food waste as discussed above, but food management practices in domestic spaces are often hidden given their private, unregulated, and geographically scattered nature. Therefore, it is complicated to track and be confident of the representativeness of data in these types of studies, which are also most often self-declarations. What is clear is that generative changes in food waste-related attitudes and behaviours could significantly impact environmental and socio-economic sustainability [18
]. To advance this project, here we present a study that is, to the authors’ best knowledge, the first paper to report changes to household food waste in NZ due to COVID-19 lockdown conditions, which at the least provide relative estimates, and qualitative information, where precise data on food waste is unavailable. This study supports other important work done in the food waste space in NZ [4
] to make recommendations towards the standardisation of food waste measurement, and recommendations about NZ’s role in helping to tackle food waste globally through its national commitments to food waste reduction.
1.2. COVID-19 Context in Aotearoa New Zealand
Globally, there is interest in the effects that COVID-19 has had and will likely continue to have on food systems. The longest COVID-19 lockdown (Levels 3 and 4) period in NZ occurred March–May 2020. Lockdown stages in NZ progressed as follows: COVID-19 Alert Level 4 came into force at 11:59 p.m. Wednesday 25 March 2020; COVID-19 Alert Level 3 came into force at 11:59 p.m. Monday 27 April 2020; COVID-19 Alert Level 2 came into force at 11:59 p.m. Wednesday 13 May 2020; COVID-19 Alert Level 1 came into force at 11:59 p.m. Monday 8 June 2020 [19
]. In NZ COVID-19 level 3 required people to stay home if possible, including working and learning from home unless not possible (e.g., in the case of essential workers required to be on location elsewhere). Level 4 instructed people to “stay at home in their bubble” (ibid.) which was often familial but could also include carers and sometimes close colleagues other than for essential personal movement. In practice, living in “bubbles” entailed severely limited travel, safe local recreational activity only, and cancellation of all gatherings and public venues with businesses operating only if they constituted essential services. Those services that were considered essential included, for example, supermarkets, pharmacies, clinics, petrol stations, and infrastructure services such as water, wastewater, transport, energy, and telecommunications.
As documented in a prior New Zealand study [20
], which presented results from the same survey on what New Zealanders consumed during lockdown, formal and informal supply chains of food to and from NZ were severely impacted by COVID-19 lockdowns. The COVID-19 pandemic changed the way that household food was managed in Aotearoa NZ. For ‘middle-class’ New Zealanders, bottlenecks in the supply of usually available foods made some experimentation in meal preparation necessary. Disrupted supply chains meant that typically available foods were less accessible, with the consequence of households needing to plan meals further in advance and more often, where slow and snaking queues had to be negotiated to enter supermarkets. Oversubscribed online delivery slots made the food shopping experience arduous or even impossible for some [21
]. Shopping trips (online or in person) were consequently more widely spaced for the majority of households. An increased number of New Zealanders suffered food poverty, resulting in a greater need for food charity and government support [22
]. Fishing and harvesting food, and church and community garden use were hindered. Such limitations generated an increase in practices such as the backyard gardening of food crops for food security, food sovereignty and general ‘food management’ concerns. These changes to behaviour all had implications for household food waste.
1.3. International Studies on Household Food Waste in COVID-19 Times
There have been numerous, global, questionnaire-based studies of COVID-19 impacts on household food waste, and several with respondent numbers comparable to this study. The below brief review of COVID-19 food waste studies considers recent larger published datasets (>1000 respondents) and their outcomes, for which the study design used was for self-declarations of domestic food waste, via online survey.
In the UK a study of 4197 participants showed domestic food waste reduced significantly in April 2020 (the early phase of the lockdown there) with a 34% reduction of wasted staples such as bread, chicken, milk, and potatoes versus pre-lockdown figures [24
]. This study also noted an increase in particular food planning behaviours, rising to 41% of those surveyed planning their supermarket shop by checking the cupboards and refrigerator, 37% organising that food, 33% ‘cooking more creatively’, and 30% of respondents starting to save leftovers in this period. An Italian study (n
= 1188) echoed the UK study, reporting that 33% of consumers perceived a substantial decrease in household food waste due to the COVID-19 lockdown, however ~45% declared that by their own perception, it was unchanged [25
]. A second Italian study (n
= 1078) similarly surveyed households during March–April 2020 [26
]. It showed that respondents spent more on food per week over lockdown (an average of €132 per week compared with €110 pre-Covid), likely due to more food being consumed at home. Making shopping lists to plan food purchases increased from 59% pre-Covid to 86.5% during lockdown. The latter study points to lacking ‘food management habits and behaviour’ as the key reasons for pre-Covid food waste figures, which according to survey responses, reduced from ~10% before COVID-19 to 6.3%.
A Dutch study undertaken between 8–17 May 2020 surveyed 1500 participants (41.8% male, 58.7% female, and 91% middle-to-high income earners) about food planning, buying, preparing, and storing behaviour, as well as self-reported food waste [27
]. It found that 26% of respondents self-declared a lower volume of food waste at home over lockdown. The reduction in food waste for this group of consumers can be explained where respondents’ increasingly planned their food in advance before going to the shop: (mean pre-COVID-19: 4.9 vs. mean during lockdown of 5.3, p
< 0.001 *) as correlated with an increased use of shopping lists, the purchase of non-perishable food items, and a reduction in impulse-buying). Further, ~40% ate at home more often, with 26% cooking more often during COVID-19 than before, and 20% spending more time on meal preparation. Interestingly, most participants (70–79%) declared that they wasted just as much food as before COVID-19, despite these other behavioural changes. Of those who did discard less (particularly fresh fruits, vegetables, and leftovers), most listed having ‘eaten everything they bought’ as the primary reason for reducing waste.
In Japan, a COVID-19 food waste survey (n
= 1959) [28
] showed that regions highly impacted by the pandemic (often metropolitan areas) appeared to be more prudent and austere about their food purchasing, considering the amount, type, and cost of domestic food waste. In contrast, residents in low-impact regions appeared to buy more ‘excessive’/’unnecessary’ food since the pandemic was declared. Buying more food than usual due to fear or anxiety, storing more food than before the lockdown, and improvising when buying groceries seemed to increase the food waste reported by the participants in a similarly oriented Spanish study (n
= 6293) [29
]. These findings chime with a Tunisian study (n
= 300), which reported that the most cited reasons for discarding food were overbuying, overcooking, and inappropriate food storage [30