Reducing food waste by simply measuring it: insights from interventions to reduce household food waste

Abstract

PurposeOvercooking and overbuying are two main causes of food waste in households. Therefore, this study tests whether two interventions, aimed at cooking planning versus purchasing planning, can reduce food waste in households by using self-report direct measurements. Because measuring household food waste can impact how much food is wasted, the effects of the mere measurement of household food waste over time were assessed as well.Design/methodology/approachA sample of 80 households was distributed into three groups (control, purchasing planning and cooking planning) and their household food waste was weighed over a period of 166 days. After the first 91 days, behavioral interventions were delivered to purchasing planning and cooking planning groups. Repeated measures ANOVA, linear regression and a two-level mixed model were used for data analysis.FindingsResults showed that the interventions were not effective in influencing the participants to reduce household food waste beyond the reduction in the control group. However, there is evidence of a mere measurement effect that caused household food waste reduction over time.Originality/valueThis study's experimental period is longer than most of the studies that tested behavioral interventions for household food waste reduction. This enabled the authors to assess the effects of repeated measurement and discover that measurement alone can bring behavioral change.

A Systematic Review of Pre-Post Studies Testing Behaviour Change Interventions to Reduce Consumer Food Waste in the Household

“…Of the grouped studies, all but one [56] incorporated a control group in the study design, reducing confounding external factors, and enabling a change in behaviour to be attributable to the success of an intervention [44,79]. Recent literature has indicated that measurement may impact on behaviour, and thus differences between the control group and treatment group are necessary to indicate if an intervention works, if all groups show a reduction in food waste post-test [13]. In Young, Russell, Robinson, and Barkemeyer's study [58], participants were placed in groups dependent on the prior self-reported awareness of campaign materials, thus it cannot be assumed that the participants were like-for-like across groups, as purposeful allocation renders the control group a quasicontrol [58,80].…”

“…The review results should be interpreted with the focused scope in mind of adult consumers within the household in countries that tend to generate more food waste. The following notable studies may be relevant for similar reviews with widened PICOS parameters: Davenport et al, 2019 [92]; Giordano et al, 2019 [25]; Neff et al, 2019 [93]; Revilla and Salet, 2018 [94]; Russell et al, 2017 [60]; Septianto et al, 2020 [95]; van Dooren et al, 2020 [96]; and Ramos et al 2023 [13]. To the authors' knowledge, there are no missing results from this review that fit the inclusion and exclusion criteria or bias due to missing results [36].…”

“…A plethora of studies have implemented interventions thought to be effective in changing food waste behaviours, such as information-sharing and education, role modelling, influencing food habits for the better (nudging), and providing feedback [8,9]. These techniques can improve awareness of one's own food waste [10,11], food management skills [12,13], and provide motivation and opportunity to change behaviour [14][15][16].…”

“…A structured and methodical approach is required to facilitate intervention testing, simultaneously by measuring 'before and after' repeated measures to determine if behaviour differs at each point [32,33], and measuring again to determine if there is any long-term impact. A growing concern here is the potential of a measurement effect that research itself may have on behaviour, which can be mitigated through the use of a control group [13]. Thus, this review turns to studies using this approach to determine the ways in which interventions to reduce consumer food waste have been implemented in the household.…”